(19)
(11)EP 3 490 249 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
22.07.2020 Bulletin 2020/30

(21)Application number: 19151248.2

(22)Date of filing:  22.05.2017
(51)International Patent Classification (IPC): 
H04N 5/60(2006.01)
G09B 21/00(2006.01)

(54)

DISPLAY DEVICE

ANZEIGEGERÄT

APPAREIL D'AFFICHAGE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 23.05.2016 JP 2016102356
29.03.2017 JP 2017066112

(43)Date of publication of application:
29.05.2019 Bulletin 2019/22

(62)Application number of the earlier application in accordance with Art. 76 EPC:
17172189.7 / 3249909

(73)Proprietor: Funai Electric Co., Ltd.
Daito Osaka 574-0013 (JP)

(72)Inventors:
  • MATSUMOTO, Masanori
    Daito, Osaka 574-0013 (JP)
  • KAMIKUBO, Ikuo
    Daito, Osaka 574-0013 (JP)
  • NISHIGAKI, Hiroshi
    Daito, Osaka 574-0013 (JP)
  • IMADA, Yuji
    Daito, Osaka 574-0013 (JP)

(74)Representative: Global IP Europe Patentanwaltskanzlei 
Pfarrstraße 14
80538 München
80538 München (DE)


(56)References cited: : 
JP-A- 2000 161 977
US-A1- 2006 287 851
JP-A- 2008 170 980
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] This application claims priority to Japanese Patent Application Nos. 2016-102356 filed on May 23, 2016 and 2017-66112 filed on March 29, 2017.

    BACKGROUND


    Field of the Invention



    [0002] The present invention generally relates to a display device. More specifically, the present invention relates to a display device including an output component that is configured to output a first signal having guidance information and a second signal having audio information related to video.

    Background Information



    [0003] A guidance device capable of outputting a first signal having guidance information and a second signal having audio information related to video is known in the art (see JP 2008-170980 A, for example).

    [0004] With the above-mentioned JP 2008-170980 A, the guidance device includes a display component, an output component, and a controller. The output component outputs guidance audio and non-guidance audio other than the guidance audio. The controller performs control to output the guidance audio at a volume output value corresponding to a volume output value of the non-guidance audio. This guidance device is configured such that the volume output value of the guidance audio is determined based on the volume setting value of the guidance device.

    [0005] JP 2000 161977 A discloses a navigation device configured to control the output volume levels of the navigation-guidance voice and the audio sound so as to increase substantially linearly as the volume setting value increases.

    SUMMARY



    [0006] With the guidance device discussed in the above-mentioned JP 2008-170980 A, however, when the volume setting value of the guidance device is set to 0 (zero; a muted state), then not only the volume output value of the non-guidance audio, but the volume output value of the guidance audio also ends up being set to 0 (zero). Therefore, when the volume setting value of the guidance device is set to 0 (zero), no guidance audio (guidance information) is issued (outputted). This is a problem in that a visually impaired user cannot be apprised of the content of the guidance audio (guidance information).

    [0007] One object is to provide a display device with which a visually impaired user can be reliably apprised of the content of guidance information even when the volume setting value of the display device has been set to 0 (zero; a muted state). The object above is achieved by a display device defined in the appended claim 1. Further advantageous effects can be achieved by preferred embodiments defined in the appended dependent claims.

    [0008] (1-1) An aspect of the present invention provides a display device comprising: a display component; an output component configured to output a first signal having guidance information and a second signal having audio information as guidance audio and non-guidance audio, respectively, the guidance information pertaining to an operation performed on the display device or a status of the display device, the audio information pertaining to content displayed on the display component; a setting component configured to perform volume setting; a table in which an output level of the first signal and output levels of the second signal are respectively associated with volume setting values, the output level of the first signal being an output volume value of the first signal, the output levels of the second signal being output volume values of the second signal; and a controller configured to control output levels of the first signal and the second signal based on the table.

    [0009] The table is configured such that the output level of the first signal written to the table can be changed by a user to a desired value. Th table is further configured to be rewritten according to a change in the written output level of the first signal such that the volume setting value of the display device is restricted to a range in which the output level of the second signal does not reach nor exceed the output level of the first signal, such that the controller sets the output level of the first signal to a value that is greater than the output level of the second signal and sets the output level of the first signal to a value greater than zero when the output level of the second signal is zero.

    [0010] (1-2) According to a preferred embodiment of the display device mentioned above, difference between the output level of the first signal and the output level of the second signal at a specific volume setting value is greater than difference between the output level of the first signal and the output level of the second signal at another volume setting value that is greater than the specific volume setting value.

    [0011] (1-3) According to another preferred embodiment of any one of the display devices mentioned above, the output level of the first signal is a value that falls within a specific range.

    [0012] [2-1] A display device as a reference example comprises a display component, an output component, a setting component, and a controller. The output component is configured to output a first signal having guidance information and a second signal having audio information pertaining to content. The setting component is configured to perform volume setting. The controller is configured to control output levels of the first signal and the second signal. The controller is configured to set the output level of the first signal to a value that is greater than or equal to the output level of the second signal, and configured to set the output level of the first signal to a value greater than zero when the output level of the second signal is zero.

    [0013] With the display device, as discussed above, the controller is provided so that the output level of the first signal having the guidance information is set to a value that is greater than or equal to the output level of the second signal having the audio information related to video or other content, and the output level of the first signal is set to a value greater than zero when the output level of the second signal is zero. Consequently, the first signal having the guidance information with a volume greater than 0 (zero) can be outputted even when a volume setting value of the display device has been set to 0 (zero). Also, the output level of the first signal is a value that is greater than or equal to the output level of the second signal even when the output level of the second signal is some value other than zero. Thus, the first signal can be outputted in addition to the second signal. As a result, even when the volume setting value of the display device has been set to 0 (zero; a muted state), a visually impaired user can be reliably apprised of the content of the guidance information by means of the first signal having the guidance information.

    [0014] [2-2] According to a preferred reference example of the display device as the reference example mentioned above, a change amount in the output level of the first signal due to a specific change in a volume setting value is a value less than or equal to a change amount in the output level of the second signal due to the specific change in the volume setting value. With this configuration, the increase (or decrease) in the output level of the first signal due to the increase (or decrease) in the volume setting value can be kept lower than the increase (or decrease) in the output level of the second signal due to the increase (or decrease) in the volume setting value. Thus, a sudden change in the output level of the first signal due to the increase (or decrease) in the volume setting value is avoided. Therefore, a visually impaired user will be able to hear the guidance information (the first signal) to the extent that simultaneously hearing the audio information related to video (the second signal) will not be hindered.

    [0015] [2-3] According to another preferred reference example of any one of the display devices as the reference examples mentioned above, a change rate in the output level of the first signal relative to a volume setting value is less than or equal to a change rate in the output level of the second signal relative to the volume setting value. For example, slopes a and b of waveforms of the first signal and the second signal are in a relation of a ≤ b. With this configuration, the slope a ≤ the slope b. Here, the waveform are indicative of characteristics of the output levels of the first signal and the second signal and a volume setting value. Thus, the increase (or decrease) in the output level of the first signal due to the increase (or decrease) in the volume setting value can be reliably kept lower than the increase (or decrease) in the output level of the second signal due to the increase (or decrease) in the volume setting value. Therefore, regardless of the increase (or decrease) in the volume setting value, a visually impaired user will reliably be able to hear the guidance information (the first signal) to the extent that hearing the audio information related to video (the second signal) will not be hindered.

    [0016] [2-4] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, the change rate in the output level of the first signal relative to the volume setting value is equal to the change rate in the output level of the second signal relative to the volume setting value for a specific range of the volume setting value.

    [0017] [2-5] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, difference between the output level of the first signal and the output level of the second signal at a specific volume setting value is greater than difference between the output level of the first signal and the output level of the second signal at a volume setting value that is greater than the specific volume setting value. With this configuration, as the volume setting value increases, the difference between the output level of the first signal and the output level of the second signal shrinks. Thus, it is less likely that the value of the output level of the guidance information (the first signal) will be too high. Also, the guidance information can be outputted at a value of an output level that is suitable for a visually impaired user.

    [0018] [2-6] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, difference between the output level of the first signal and the output level of the second signal at a specific volume setting value and difference between the output level of the first signal and the output level of the second signal at a volume setting value that is different from the specific volume setting value are substantially equal values over a range from a first volume setting value to a second volume setting value that is greater than the first volume setting value. With this configuration, even if the volume setting value is changed, the first signal can be outputted at a value of an output level that is greater than the value of the output level of the second signal by a specific amount of volume (a volume of a constant value). Therefore, a visually impaired user can easily hear the first signal even if the volume setting value has been changed.

    [0019] [2-7] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, with a configuration in which the difference between the output level of the first signal and the output level of the second signal at the specific volume setting value and the difference between the output level of the first signal and the output level of the second signal at the volume setting value that is different from this specific volume setting value are substantially equal values, the output level of the first signal is a value that falls within a specific range over a range of volume setting values that are greater than the second volume setting value. With this configuration, even if the output level of the first signal is set to a volume setting value that is greater than the second volume setting value, the output level of the first signal is maintained at the maximum value or near the maximum value (within a specific range). Thus, over a range of volume setting values that are greater than or equal to a volume setting value at which the output level of the first signal is at its highest, a situation will be avoided in which the first signal having the guidance information becomes a hindrance that makes it hard to hear the second signal indicating the audio information related to video.

    [0020] [2-8] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, with a configuration in which the difference between the output level of the first signal and the output level of the second signal at the specific volume setting value and the difference between the output level of the first signal and the output level of the second signal at the volume setting value that is different from the specific volume setting value are substantially equal values, the output level of the first signal is a value that falls within a specific range over a range of volume setting values that are less than or equal to the first volume setting value. With this configuration, as opposed to a situation in which the output level of the first signal goes down as the volume setting value decreases, a visually impaired user will be able to properly hear the first signal whose output level is maintained within the specific range, even if the volume setting value decreases.

    [0021] [2-9] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, the first volume setting value is a volume setting value at a midpoint in a settable volume range. With this configuration, the output level of the first signal can be maintained within a specific range even if the volume setting value decreases in a range at or below the midpoint of the settable volume range. Thus, a visually impaired user will be able to easily hear the first signal whose output level is maintained within the specific range. Also, over a range in which the volume setting value is above the midpoint, the user can properly hear both the first signal having the guidance information and the second signal having the audio information related to video.

    [0022] [2-10] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, with a configuration in which the difference between the output level of the first signal and the output level of the second signal at the specific volume setting value and the difference between the output level of the first signal and the output level of the second signal at the volume setting value that is different from the specific volume setting value are substantially equal values, the output level of the first signal and the output level of the second signal are substantially equal values at the specific volume setting value over the range from the first volume setting value to the second volume setting value. With this configuration, over the range from the first volume setting value to the second volume setting value, the value of the output level of the first signal having the guidance information is kept from going too high, while this first signal can be outputted at a proper value of an output level.

    [0023] [2-11] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, with a configuration in which the difference between the output level of the first signal and the output level of the second signal at the specific volume setting value and the difference between the output level of the first signal and the output level of the second signal at the volume setting value that is different from the specific volume setting value are substantially equal values, the output level of the first signal and the output level of the second signal are different values at the specific volume setting value over the range from the first volume setting value to the second volume setting value. With this configuration, even if the volume setting value is changed, the first signal can be outputted at a value of an output level that is greater than the value of the output level of the second signal by a specific output level (volume). Thus, a visually impaired user can easily hear the first signal.

    [0024] [2-12] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, the output level of the first signal is a value that falls within a specific range. With this configuration, if the output level of the first signal is set to a proper value, then no matter what the volume setting value is, a visually impaired user can hear the first signal having the guidance information at a uniform volume that is easy to hear.

    [0025] [2-13] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, a settable volume range of the setting component is set to a range in which the output level of the first signal is greater than or equal to the output level of the second signal. With this configuration, no matter what the volume setting value is within the settable volume range of the setting component, the value of the output level of the first signal can be set to be greater than or equal to the value of the output level of the second signal. Thus, a visually impaired user can reliably hear the first signal having the guidance information while the second signal having the audio information related to video is being outputted.

    [0026] [2-14] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, the display device further comprises a table in which the output levels of the first signal and the second signal are respectively associated with volume setting values corresponding to the volume setting by the setting component. The controller is configured to control the output levels of the first signal and the second signal based on the table. With this configuration, even if the output level of the second signal in the display device is set to 0 (zero), as opposed to a situation in which computation is performed each time so that the output level of the first signal will not be 0 (zero), by using the table, it can be quickly prevented that the output level of the first signal will be 0 (zero), and computation will impose an extra load on the controller. Also, even if the output level of the second signal in the display device is set to something other than 0 (zero), the table can be used to quickly keep the output level of the first signal at or above the output level of the second signal.

    [0027] [2-15] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, the table includes a first table in which specific output levels of the first signal are associated with volume setting values, and a second table in which output levels different from the specific output levels of the first signal are associated with the volume setting values. The controller is configured to control the output level of the first signal based on either the first table or the second table. With this configuration, the output level of the first signal can be set to a more suitable output level (output volume value) according to the content of the first signal by suitably switching between the first table and second table. For instance, even when giving a notification without which the convenience of a visually impaired user would be compromised (when outputting information related to channel changing as the guidance information), the guidance information (first signal) can be reliably conveyed.

    [0028] [2-16] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, the controller is configured to perform control to change both the output levels of the first signal and the second signal along with a change in a volume setting value. With this configuration, the first signal and second signal can both be changed to the values of the output levels that are suited to the usage situation, in conjunction with the volume setting value.

    [0029] [2-17] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, the first signal is audio that conveys at least one of information related to an operation carried out on the display device, and information related to status of the display device. With this configuration, the information related to the operations performed on the display device, and the information related to the status of the display device can be conveyed to a visually impaired user.

    [0030] [2-18] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, the second signal is audio related to video displayed on the display component. With this configuration, the first signal can be outputted even with a setting such that audio related to video displayed on the display component is at a first volume (not outputted).

    [0031] [2-19] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, the display device further comprises a receiver configured to receive broadcast signals. The second signal corresponds to audio from the receiver. With this configuration, the first signal can be easily outputted so that the user can see and hear it, even when the volume setting value at which the second signal included in the broadcast signal is outputted has been set to a first volume.

    [0032] [2-20] According to further another preferred reference example of any one of the display devices as the reference examples mentioned above, the display device further comprises an input unit to which audio from an external device is inputted. The second signal corresponds to the audio inputted to the input unit. With this configuration, the first signal can be easily outputted so that the user can see and hear it, even when the volume setting value at which the second signal included in content is outputted form the external device has been set to a first volume.

    [0033] With the present invention, as discussed above, even when the volume setting value of the display device has been set to 0 (zero; a muted state), the contents of the guidance information can be reliably conveyed to a visually impaired user.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0034] Referring now to the attached drawings which form a part of this original disclosure:

    FIG. 1 is a block diagram of a display device pertaining to a first reference example;

    FIG. 2 is a table of correlation between a volume setting value and output volume values for guidance audio and non-guidance audio in the display device pertaining to the first reference example;

    FIG. 3 is a table of correlation between a volume setting value and output volume values for guidance audio and non-guidance audio in a display device pertaining to a second reference example;

    FIG. 4 is a table of correlation between a volume setting value and output volume values for guidance audio and non-guidance audio in a display device pertaining to a third reference example;

    FIG. 5 is a table of correlation between a volume setting value and output volume values for guidance audio and non-guidance audio in a display device pertaining to a fourth reference example;

    FIG. 6 is a table of correlation between a volume setting value and output volume values for guidance audio and non-guidance audio in a display device pertaining to an embodiment of the present invention;

    FIG. 7 is a table of correlation between a volume setting value and output volume values for guidance audio and non-guidance audio in a display device pertaining to a modification example of the fourth reference example; and

    FIG. 8 is a graph visually depicting correlation (table) between a volume setting value and output volume values for guidance audio and non-guidance audio in a display device pertaining to a modification example.


    DETAILED DESCRIPTION OF REFERENCE EXAMPLES AND EMBODIMENT



    [0035] Selected preferred reference examples and an embodiment will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the reference examples and the embodiment are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims.

    FIRST REFERENCE EXAMPLE


    Overall Configuration of Display Device



    [0036] First, the configuration of a display device 100 pertaining to a first reference example will be described through reference to FIGS. 1 and 2.

    [0037] As shown in FIG. 1, the display device 100 is a television set or other display device that can be operated with a remote control 50. A setting component 51 (volume buttons) on the remote control 50 allows the volume setting value to be changed for the display device 100. Various setting components 52 (buttons) on the remote control 50 can be used for various operations (such as changing the channel) on the display device 100. The display device 100 can output "guidance audio" or other such audio. The guidance audio or other such audio conveys or notifies information related to operations performed on the display device 100 using the remote control 50, or information related to the status of the display device 100. Also, the display device 100 can output "non-guidance audio" that is different from the guidance audio. In the first reference example, the non-guidance audio is, for example, audio related to video that is displayed on a display component 2 of the display device 100. However, the non-guidance audio is not limited to this. The non-guidance audio can be audio related to content other than the video. The guidance audio and the non-guidance audio are examples, respectively, of the "first signal having guidance information" and the "second signal having audio information related to video" of the present disclosure. In other words, the non-guidance audio is the audio of the displayed video program. The guidance audio is other than this non-guidance audio.

    [0038] The display device 100 includes an SoC (system on chip) 1. The SoC 1 controls the entire display device 100. The SoC 1 will be discussed in detail below. Also, the display device 100 includes the display component 2, which displays video. The display component 2 is, for example, a liquid crystal display (LCD) in the illustrated reference example. However, the display component 2 can be different type of display. The display device 100 includes an amplifier 3 that amplifies audio signals.

    [0039] Also, the display device 100 includes an output component 4 that outputs audio signals amplified by the amplifier 3. The output component 4 is disposed between the amplifier 3 and a speaker 9. The output component 4 outputs the guidance audio and the non-guidance audio. The display device 100 outputs the guidance audio and the non-guidance audio at output volume values corresponding to a volume setting value set with the setting component 51 of the remote control 50. The output volume values are an example of the "output level" of the present disclosure.

    [0040] The display device 100 also includes a remote control signal receiver 5. The remote control signal receiver 5 receives signals (remote control signals) issuing from the remote control 50. The display device 100 also comprises a receiver (tuner) 6 that receives broadcast signals. The display device 100 also comprises a connector 7. The connector 7 is a terminal that conforms to the HDMI™ (High-Definition Multimedia Interface) standard, for example. This connector 7 receives audio and video signals conforming to the HDMI™ standard and transmitted from an external content reproduction device (not shown) that is connected via the connector 7. Of course, the connector 7 can be different type of connector.

    [0041] The display device 100 further comprises a connector 8. The connector 8 is a video input terminal, for example. The connector 8 receives video signals transmitted from an external content reproduction device (not shown) that is connected via the connector 8. The term "video signal" includes both audio signals and video signals.

    Detailed Configuration of SoC



    [0042] The SoC 1 includes various kinds of processor (CPU). More specifically, the SoC 1 comprises a video signal processor 11. The video signal processor 11 includes a CPU. The video signal processor 11 has the function of processing video data included in a broadcast signal received by the receiver 6, and outputting the data to the display component 2. The video signal processor 11 also has the function of processing video data of a video signal or video data conforming to the HDMI™ standard and received via the connector 7 or 8, and outputting the data to the display component 2.

    [0043] The SoC 1 also comprises an audio signal processor 12. The audio signal processor 12 includes a CPU. The audio signal processor 12 has the function of processing audio data included in a broadcast signal received by the receiver 6, and outputting the data to an audio output processor 14. The audio signal processor 12 also has the function of processing audio data of a video signal or audio data conforming to the HDMI™ standard and received via the connector 7 or 8, and outputting the data to the audio output processor 14. The SoC 1 also comprises a remote control reception signal processor 13. The remote control reception signal processor 13 includes a CPU, and has the function of processing signals from the remote control 50 received by the remote control signal receiver 5.

    [0044] The SoC 1 also comprises the audio output processor 14. The audio output processor 14 includes a CPU. The audio output processor 14 performs control processing related to audio output. The output component 4 outputs audio signals based on signals processed by the audio output processor 14. The audio output processor 14 also has a memory area (storage component) 140. The memory area 140 stores an output volume value table T1. As shown in FIG. 2, the output volume value table T1 is a table in which output volume values for the non-guidance audio and output volume values for the guidance audio are associated with volume setting values. The graph at the bottom in FIG. 2 is a plot of the numerical values given in the output volume value table T1, with the horizontal axis showing the volume setting value and the vertical axis the output volume value. In the graph in FIG. 2, the solid line indicates the output volume value of the guidance audio versus the volume setting value, while the broken line indicates the output volume value of the non-guidance audio versus the volume setting value. The output volume value table T1 is an example of the "table" of the present disclosure.

    [0045] The audio output processor 14 outputs the non-guidance audio processed by the audio signal processor 12 and the guidance audio produced by a guidance audio processor 15 (discussed below), based on the output volume value table T1. As shown in FIG. 1, the SoC 1 also comprises the guidance audio processor 15. The guidance audio processor 15 produces guidance audio. The audio output processor 14 is an example of the "controller" of the present disclosure.

    [0046] As shown in FIG. 2, in the first reference example, the audio output processor 14 (see FIG. 1) performs control so that when the output volume value of the non-guidance audio has been set to "0 (a muted state)" (hereinafter referred to as a 0 level) by setting the volume setting value to 0 level by the setting component 51 of the remote control 50 (see FIG. 1), the guidance audio is outputted from the output component 4 at an output volume value that is greater than this 0 level. In this case, the audio output processor 14 performs control to output the guidance audio at an output volume value (e.g., the 20 level in this reference example) that is greater than the 0 level (a muted state) based on the output volume value table T1. In the output volume value table T1, the output volume values of the non-guidance audio and the output volume values of the guidance audio are associated with the volume setting values. The audio output processor 14 performs audio output control that makes use of the output volume value table T1 in which the output volume value of guidance audio will not go to the 0 level for each of the volume setting values. Also, the configuration is such that as the volume setting value increases, the output volume value of the guidance audio is also increased. Therefore, a visually impaired user is able to listen to the non-guidance audio while easily hearing the guidance audio as well.

    [0047] Also, in the first reference example, the audio output processor 14 performs control in which the volume of the guidance audio is set to be greater than or equal to the volume of the non-guidance audio when the volume of the non-guidance audio is not at the 0 level. More precisely, in the range between the 0 level (the minimum level) and 99 over which the volume setting value and the output volume value of the non-guidance audio can be varied, the guidance audio is outputted at an output volume value that is greater than the 0 level. Also, at the 100 level (the maximum level), which is the upper limit to the volume setting value and the output volume value of the non-guidance audio, the volume of the non-guidance audio and the volume of the guidance audio are substantially the same. Specifically, the audio output processor 14 performs control so that when the guidance audio is outputted, it will always be outputted at an output volume value that is greater than the 0 level. Therefore, it is stipulated ahead of time in the output volume value table T1 that the audio output processor 14 performs audio output control such that the output volume value of the guidance audio will be greater than the output volume value of the non-guidance audio when the volume setting value is between the 0 level (minimum level) and 99, and that the output volume value of the guidance audio will be equal to the output volume value of the non-guidance audio when the volume setting value is 100 (maximum value).

    [0048] Also, in the first reference example, the difference between the output volume values for the guidance audio at a specific volume setting value and a volume setting value that is different from this specific volume setting value, is less than the difference between the output volume values for the non-guidance audio at the specific volume setting value and the volume setting value that is different from this specific volume setting value. More specifically, the output volume value table T1 is configured such that, in the graph in FIG. 2, the output volume value for the guidance audio and the output volume value for the non-guidance audio increase (decrease) substantially linearly as the volume setting value (horizontal axis) increases (decreases). Also, the differential between the output volume value of the guidance audio at a volume setting value V1 and the output volume value of the guidance audio at a volume setting value V2 that is greater than this volume setting value V1 (the slope a of the linear plot (waveform) indicated by the solid line between the volume setting values V1 and V2; the rate of change (change rate) a) is less than the differential in the output volume value of the non-guidance audio in the same change from the volume setting value V1 to V2 (the slope b of the linear plot (waveform) indicated by the broken line between the volume setting values V1 and V2; the rate of change (change rate) b) (a < b). In other words, the rate of change a in the output volume value of the guidance audio to the volume setting value is less than the rate of change b in the output volume value of the non-guidance audio to the volume setting value. Therefore, the increase (or decrease) in the output volume value of the guidance audio is kept lower than the increase (or decrease) in the output volume value of the non-guidance audio during an increase (or decrease) in the volume setting value. The plot indicated by the solid line in FIG. 2 is a waveform indicating the characteristics of the volume setting value and the output volume value of the guidance audio, while the plot indicated by the broken line in FIG. 2 is a waveform indicating the characteristics of the volume setting value and the output volume value of the non-guidance audio.

    [0049] Also, the difference between the output volume value of the guidance audio and the output volume value of the non-guidance audio at a specific volume setting value is greater than the difference between the output volume value of the guidance audio and the output volume value of the non-guidance audio at a volume setting value that is greater than this specific volume setting value. More specifically, in the graph in FIG. 2, the volume difference Δ2 between the output volume value of the guidance audio and the output volume value of the non-guidance audio at the volume setting value V2 is less than the volume difference Δ1 between the output volume value of the guidance audio and the output volume value of the non-guidance audio at the volume setting value V1. In other words, as the volume setting value increases, the volume difference Δ decreases from the volume difference Δ1 to the volume difference Δ2. Conversely, as the volume setting value decreases, the volume difference Δ increases from the volume difference Δ2 to the volume difference Δ1. Specifically, the audio output processor 14 uses the output volume value table T1 to perform volume output control set such that, over the entire range over which the volume setting value can be varied (from the 0 level to 100), as the volume setting value increases, the difference between the output volume value of the guidance audio and the output volume value of the non-guidance audio (the volume difference Δ) will decrease. In this case, the audio output processor 14 performs control to set (vary) both the output volume value of the non-guidance audio and the output volume value of the guidance audio so that the output volume value of the guidance audio increases by a specific volume difference Δ relative to the output volume value of the non-guidance audio as the volume setting value is varied. Consequently, the increase (or decrease) in the output volume value of the guidance audio is kept lower than the increase (or decrease) in the output volume value of the non-guidance audio during an increase (or decrease) in the volume setting value.

    [0050] The audio output processor 14 performs control to output the guidance audio at an output volume value that is greater than the 0 level over the entire range over which the volume setting value can be varied (from the 0 level to 100). Also, the audio output processor 14 performs control to set both the output volume value of the non-guidance audio and the output volume value of the guidance audio as the volume setting value is varied. Also, over the entire range over which the volume setting value can be varied (from the 0 level to 100), the guidance audio linearly changes with respect to changes in the volume setting value (the graph in FIG. 2 changes linearly). The display device 100 in the first reference example is configured as above.

    Effect of First Reference Example



    [0051] The following effect can be obtained with the first reference example.

    [0052] As discussed above, with the first reference example, the audio output processor 14 is provided to set the output volume value (output level) of the guidance audio having the guidance information to a value that is greater than or equal to the output volume value (output level) of the non-guidance audio having the audio information related to video, and to set the output volume value (output level) of the guidance audio to a value that is greater than zero when the output volume value (output level) of the non-guidance audio is at the 0 level (a muted state). Consequently, even when the volume setting value of the display device 100 has been set to the 0 level, the guidance audio can be outputted at an output volume value that is greater than the 0 level. Also, even when the output volume value of the non-guidance audio is a value other than the 0 level, the output volume value of the guidance audio will be a value greater than or equal to the output volume value of the non-guidance audio. Thus, the guidance audio can be outputted in addition to the non-guidance audio. As a result of all this, even when the volume setting value of the display device 100 has been set to the 0 level (a muted state), a visually impaired user can be reliably apprised of the content of the guidance audio.

    [0053] Also, with the first reference example, the change amount in the output volume value of the guidance audio due to a specific change in the volume setting value (such as a change from V1 to V2) will be a value less than or equal to the change amount in the output volume value of the non-guidance audio due to the specific change. Consequently, the increase (or decrease) in the output volume value of the guidance audio due to the increase (or decrease) in the volume setting value can be kept lower than the increase (or decrease) in the output volume value of the non-guidance audio due to the increase (or decrease) in the volume setting value. Thus, a sudden change in the output volume value of the guidance audio due to the increase (or decrease) in the volume setting value is avoided. Therefore, a visually impaired user will be able to hear the guidance audio to the extent that simultaneously hearing audio related to video (the non-guidance audio) will not be hindered.

    [0054] Also, in the first reference example, the rate of change a in the output volume value of the guidance audio with respect to a change in the volume setting value (the horizontal axis in the graph in FIG. 2) (the slope a of the plot (waveform) indicated by the solid line between the volume setting values V1 and V2) and the rate of change b in the output volume value of the non-guidance audio (the slope b of the plot (waveform) indicated by the broken line between the volume setting values V1 and V2) are in a relation of a < b. Consequently, because the slope a is less than the slope b, the increase (or decrease) in the output volume value of the guidance audio due to the increase (or decrease) in the volume setting value can be reliably kept lower than the increase (or decrease) in the output volume value of the non-guidance audio due to the increase (or decrease) in the volume setting value. Therefore, regardless of the increase (or decrease) in the volume setting value, a visually impaired user will reliably be able to hear the guidance information to the extent that hearing the audio information related to video will not be hindered.

    [0055] Also, in the first reference example, the volume difference Δ1 between the output volume value of the guidance audio and the output volume value of the non-guidance audio at the volume setting value V1 is greater than the volume difference Δ2 between the output volume value of the guidance audio and the output volume value of the non-guidance audio at the volume setting value V2, which is greater than the volume setting value V1. Consequently, as the volume setting value increases, the volume difference Δ between the output volume value of the guidance audio and the output volume value of the non-guidance audio shrinks from the volume difference Δ1 to the volume difference Δ2. Thus, it is less likely that the output volume value of the guidance information will be too high. Also, the guidance information can be outputted at an output volume value that is suitable for a visually impaired user.

    [0056] Also, in the first reference example, the output volume value table T1 is provided in which output volume values (output levels) of the guidance audio and the non-guidance audio are associated with volume setting values corresponding to the volume setting of the setting component 51. The audio output processor 14 controls the output volume values (output levels) of the guidance audio and the non-guidance audio based on the output volume value table T1. Consequently, even if the output volume value of the non-guidance audio has been set to the 0 level in the display device 100, as opposed to a situation in which computation is performed each time so that the output volume value of the guidance audio will not be at the 0 level, by using the output volume value table T1, it can be quickly prevented that the output volume value of the guidance audio will be at the 0 level, and that computation will impose an extra load on the audio output processor 14. Also, even if the output volume value of the non-guidance audio in the display device 100 is set to something other than the 0 level, the output volume value table T1 can be used to quickly keep the output volume value of the guidance audio at or above the output volume value of the non-guidance audio.

    [0057] Also, in the first reference example, the audio output processor 14 performs control to change the output volume values (output levels) of both the guidance audio and the non-guidance audio as the volume setting value changes. Consequently, both the guidance audio and the non-guidance audio can be changed to an output volume value that suits the usage situation, in conjunction with the volume setting value.

    [0058] Also, in the first reference example, the guidance audio is audio that conveys information related to an operation carried out on the display device 100, and information related to the status of the display device 100. Consequently, the information related to operations performed on the display device 100, and the information related to the status of the display device 100 can be conveyed to a visually impaired user.

    [0059] Also, in the first reference example, the non-guidance audio is audio related to video displayed on the display component 2. Consequently, the guidance audio can be outputted even with a setting such that audio related to video displayed on the display component 2 is at the 0 level (a muted state).

    [0060] Also, in the first reference example, the receiver 6 that receives broadcast signals is provided, and the non-guidance audio corresponds to audio from the receiver 6. Consequently, the guidance audio can be easily outputted so that the user can see and hear it, even when the volume setting value at which the audio included in the broadcast signal (the non-guidance audio) is outputted has been set to the 0 level (a muted state).

    [0061] Also, in the first reference example, the connector 7 (e.g., the input unit) is provided for connecting to a content reproduction device (e.g., an external device), and the non-guidance audio corresponds to audio inputted from the connector 7. Consequently, even if the volume setting value at which audio included in content from the content reproduction device (the non-guidance audio) is outputted has been set to the 0 level (a muted state), the guidance audio can still be easily outputted so that the user can see and hear it.

    [0062] Also, in the first reference example, the audio output processor 14 performs control to set both the output volume value of the non-guidance audio and the output volume value of the guidance audio so that as the volume setting value is changed, the output volume value of the guidance audio becomes greater by a specific volume difference Δ than the output volume value of the non-guidance audio. Consequently, even if the volume setting value is changed, the guidance audio can be outputted at an output volume value that is greater by the specific volume difference than the output volume value of the non-guidance audio. Thus, the guidance audio can be easily heard.

    [0063] Also, in the first reference example, the memory area (storage component) 140 is provided to store the output volume value table T1. Consequently, the output volume value table T1 stored in the memory area (storage component) 140 can be used to quickly perform control so that the output volume value of the guidance audio does not go to the 0 level (a muted state).

    [0064] In the illustrated reference example, the display device 100 comprises the display component 2, the output component 4, the setting component 51, and the audio output processor 14. The output component 4 outputs the guidance audio having the guidance information and the non-guidance audio having the information related to video. The setting component 51 performs the volume setting. The audio output processor 14 controls the output levels of the guidance audio and the non-guidance audio. The audio output processor 14 sets the output level of the guidance audio to a value that is greater than or equal to the output level of the non-guidance audio, and sets the output level of the guidance audio to a value greater than zero when the output level of the non-guidance audio is zero.

    SECOND REFERENCE EXAMPLE



    [0065] The configuration of a display device 200 pertaining to a second reference example will now be described through reference to FIGS. 1 and 3. In the first reference example, the volume difference Δ between the output volume value of the guidance audio and the output volume value of the non-guidance audio decreases as the volume setting value increases over the entire range over which the volume setting value can be varied. On the other hand, in this second reference example, the volume difference Δ between the output volume value of the guidance audio and the output volume value of the non-guidance audio is decreased as the volume setting value increases over part of the range over which the volume setting value can be varied. Except for a difference in the output volume value table, the device configuration in the second reference example is substantially the same as the device configuration in the first reference example above. The output volume value table T2 is also an example of the "table" of the present disclosure.

    [0066] As shown in FIG. 1, the output volume value table T2 is stored in a memory area (storage component) 240 of an audio output processor 214. In the second reference example, the audio output processor 214 performs control to output the guidance audio at an output volume value that is greater than the 0 level, based on the output volume value table T2. That is, as shown in FIG. 3, the audio output processor 214 performs audio output control using the output volume value table T2 set so that the output volume value of the guidance audio will not drop to the 0 level. The audio output processor 214 is an example of the "controller" of the present disclosure.

    [0067] The audio output processor 214 performs control to set the output volume value of the guidance audio so as to produce a rate of change that is less than a rate of change in the output volume value of the non-guidance audio with respect to the volume setting value. Also, the audio output processor 214 performs control to set both the output volume value of the non-guidance audio and the output volume value of the guidance audio so that the output volume value of the guidance audio will be greater by a specific volume difference Δc than the output volume value of the non-guidance audio as the volume setting value is changed. More precisely, the audio output processor 214 performs control to set both the output volume value of the non-guidance audio and the output volume value of the guidance audio so that the output volume value of the guidance audio will be greater by the specific volume difference Δc than the output volume value of the non-guidance audio at a volume setting value that is less than a volume setting value at which the output volume value of the guidance audio is at its maximum (such as the volume setting value Vc) as the volume setting value is changed. In other words, over the range from the 0 level to the volume setting value Vc that is greater than the 0 level, the volume difference Δ1 between the output volume value of the guidance audio and the output volume value of the non-guidance audio at the volume setting value V1 is substantially equal to the volume difference Δ2 between the output volume value of the guidance audio and the output volume value of the non-guidance audio at the volume setting value V2, which is different from this volume setting value V1 (Δ1 ≈ Δ2 ≈ Δc). Over the range from the 0 level to the volume setting value Vc, the output volume value of the guidance audio at the volume setting value V1 (or the volume setting value V2) is different from the output volume value of the non-guidance audio. The 0 level and the volume setting value Vc are respectively examples of the "first volume setting value" and the "second volume setting value" of the present disclosure.

    [0068] Also, the audio output processor 214 performs control to keep the output volume value of the guidance audio constant (at the 100 level) at a volume setting value that is greater than or equal to the volume setting value (the volume setting value Vc) at which the output volume value of the guidance audio is at its maximum. That is, over the range of the volume setting values greater than the volume setting value Vc, the output volume value of the guidance audio is set to fall within a specific range (constant at the 100 level).

    [0069] As discussed above, in the second reference example, the output volume value of the guidance audio changes at the same constant rate (the slope of the plot) as the output volume value of the non-guidance audio over the range from the 0 level to the volume setting value up to the volume setting value Vc. In other words, the rate of change in the output volume value of the guidance audio to the volume setting value is equal to the rate of change in the output volume value of the non-guidance audio to the volume setting value for a specific range of the volume setting value (i.e., for the range from the 0 level to the volume setting value Vc). On the other hand, the rate of change in the output volume value of the guidance audio to the volume setting value is less than the rate of change in the output volume value of the non-guidance audio to the volume setting value for a specific range of the volume setting value (i.e., for the range from the volume setting value Vc to the 100 level).

    [0070] Also, the output volume value of the guidance audio is constant (at the 100 level) over the range of the volume setting values from the volume setting value Vc and beyond. The rest of the configuration of the second reference example is the same as in the first reference example above.

    Effect of Second Reference Example



    [0071] The following effect can be obtained with the second reference example.

    [0072] In the second reference example, the audio output processor 214 is provided so that the output volume value of the guidance audio will be greater than the 0 level when the output volume value of the non-guidance audio is at the 0 level (a muted state), and the output volume value of the guidance audio will be greater than or equal to the output volume value of the non-guidance audio when the output volume value of the non-guidance audio is something other than the 0 level. Consequently, just as in the first reference example above, even if the volume setting value of the display device 200 has been set to the 0 level (a muted state), the content of the guidance can be reliably conveyed to a visually impaired user by means of the guidance audio at an output volume value that is greater than the 0 level.

    [0073] Also, in the second reference example, over a range from the 0 level to the volume setting value Vc, the volume difference Δ1 between the output volume value of the guidance audio and the output volume value of the non-guidance audio at the volume setting value V1 and the volume difference Δ2 between the output volume value of the guidance audio and the output volume value of the non-guidance audio at the volume setting value V2, which is different from the volume setting value V1, are substantially equal values. Consequently, even if the volume setting value is changed, the guidance audio can be outputted at an output volume value that is greater by a specific volume (a volume of a constant value) than the output volume value of the non-guidance audio. Therefore, a visually impaired user can easily hear the guidance audio even if the volume setting value has been changed.

    [0074] Also, in the second reference example, the output volume value of the guidance audio is within a specific range (a constant 100 level). Consequently, even if the output volume value of the guidance audio is set to a volume setting value that is greater than the volume setting value Vc, the output volume value of the guidance audio will be maintained at the maximum value or near the maximum value (a constant 100 level). Thus, over a range of volume setting values that are greater than or equal to the volume setting value at which the output volume value of the guidance audio is at its highest, a situation will be avoided in which the guidance audio becomes a hindrance that makes it hard to hear the non-guidance audio.

    [0075] Also, in the second reference example, over the range from the 0 level to the volume setting value Vc, the output volume value of the guidance audio at the volume setting value V1 (volume setting value V2) is made to be different from the output volume value of the non-guidance audio. Consequently, even if the volume setting value is changed, the guidance audio can be outputted at an output volume value that is greater by a specific output volume value (volume difference Δc) than the output volume value of the non-guidance audio. Thus, a visually impaired user can easily hear the guidance audio.

    [0076] Also, in the second reference example, the audio output processor 214 is configured to perform control to set both the output volume value of the non-guidance audio and the output volume value of the guidance audio so that as the volume setting value is changed, the output volume value of the guidance audio becomes greater by the volume difference Δc than the output volume value of the non-guidance audio. Consequently, even if the volume setting value is changed, the guidance audio can be outputted at an output volume value that is greater by the specific volume difference than the output volume value of the non-guidance audio. The rest of the effect of the second reference example is the same as in the first reference example above.

    THIRD REFERENCE EXAMPLE



    [0077] The configuration of a display device 300 pertaining to a third reference example will now be described through reference to FIGS. 1 and 4. In the first reference example, the output volume value of the guidance audio increases over the entire range over which the volume setting value can be varied when the volume setting value increases. On the other hand, in this third reference example, when the volume setting value is increased, the output volume value of the guidance audio is increased over just part of the range over which the volume setting value can be varied. Except for a difference in the output volume value table, the device configuration in the third reference example is substantially the same as the device configuration in the first reference example above.

    [0078] As shown in FIG. 1, an output volume value table T3 is stored in a memory area (storage component) 340 of an audio output processor 314. In the third reference example, the audio output processor 314 performs control to output the guidance audio at an output volume value that is greater than the 0 level, based on the output volume value table T3. That is, as shown in FIG. 4, the audio output processor 314 performs audio output control using the output volume value table T3 set so that the output volume value of the guidance audio will not drop to the 0 level for each volume setting values. The audio output processor 314 is an example of the "controller" of the present disclosure. The output volume value table T3 is also an example of the "table" of the present disclosure.

    [0079] In the third reference example, the audio output processor 314 performs control to keep the output volume value of the guidance audio constant (within a specific range) over the range in which the volume setting value is from the 0 level to a value (volume setting value Vd) that is greater than the 0 level and less than the maximum volume setting value, out of the settable range of the volume setting value. The audio output processor 314 performs control to keep the output volume value of the guidance audio constant (within a specific range) over the range in which the volume setting value is from the 0 level to a value that is less than one half (less than the 50 level) the maximum volume setting value (the 100 level), out of the settable range of the volume setting value. The audio output processor 314 also performs control to make the output volume value of the guidance audio substantially match the output volume value of the non-guidance audio over a range from a value that is at least half the maximum volume setting value (at least the 50 level) to no more than the maximum volume setting value (no more than the 100 level). The volume setting value Vd and the maximum volume setting value (the 100 level) are respectively examples of the "first volume setting value" and the "second volume setting value" of the present disclosure.

    [0080] More precisely, the audio output processor 314 performs control to set both the output volume value of the non-guidance audio and the output volume value of the guidance audio so that the output volume value of the guidance audio will be greater by a specific volume difference Δd than the output volume value of the non-guidance audio as the volume setting value changes, at a volume setting value that is less than the volume setting value Vd. Also, the audio output processor 314 performs control to keep the output volume value of the guidance audio constant at a volume setting value that is less than the volume setting value Vd. Also, the constant output volume value of the guidance audio is made to substantially match the output volume value of the non-guidance audio at the volume setting value Vd. In the third reference example, the volume setting value Vd is the "50 level" (the midpoint (half value) of the maximum volume setting value). However, the volume setting value Vd can instead be some other value. Specifically, this volume setting value Vd can be changed to the desired value by the user.

    [0081] Also, the audio output processor 314 performs control to set the output volume value of the guidance audio and the output volume value of the non-guidance audio at the volume setting value Vd to substantially equal values over the range from the volume setting value Vd to the maximum volume setting value (100 level) that is greater than the volume setting value Vd. In this case, the audio output processor 314 performs audio output processing so that the rate of change in the output volume value of the guidance audio with respect to the volume setting value (the slope of the solid line plot (waveform)) is a value that is substantially equal to the rate of change in the output volume value of the non-guidance audio with respect to the volume setting value (the slope of the broken line plot (waveform)) as the volume setting value changes, at a volume setting value greater than or equal to the volume setting value Vd. In other words, the rate of change in the output volume value of the guidance audio to the volume setting value is equal to the rate of change in the output volume value of the non-guidance audio to the volume setting value for a specific range of the volume setting value (i.e., for the range from the 0 level to the volume setting value Vc). On the other hand, the rate of change in the output volume value of the guidance audio to the volume setting value is less than the rate of change in the output volume value of the non-guidance audio to the volume setting value for a specific range of the volume setting value (i.e., for the range from the 0 level to the volume setting value Vd).

    [0082] As discussed above, with the third reference example, the output volume value of the guidance audio is constant over the range of volume setting values up to the volume setting value Vd (the slope of the solid line plot is approximately equal to zero), and varies at a constant rate that is substantially equal to that of the non-guidance audio over the range of volume setting values from the volume setting value Vc and beyond. The rest of the configuration of the third reference example is the same as in the first reference example above.

    Effect of Third Reference Example



    [0083] The following effect can be obtained with the third reference example.

    [0084] With the third reference example, the audio output processor 314 is provided to set the output volume value of the guidance audio to be greater than the 0 level when the output volume value of the non-guidance audio is at the 0 level (a muted state), and to set the output volume value of the guidance audio to at least the output volume value of the non-guidance audio when the output volume value of the non-guidance audio is something other than the 0 level. Consequently, just as in the first reference example above, even when the volume setting value of the display device 300 has been set to the 0 level (a muted state), a visually impaired user can be reliably apprised of the content of the guidance by means of the guidance audio at an output volume value that is greater than the 0 level.

    [0085] Also, with the third reference example, over the range of the volume setting values less than or equal to the volume setting value Vd, the output volume value of the guidance audio is set to fall within a specific range (a constant value). Consequently, unlike the situation when the output volume value of the guidance audio similarly drops as the volume setting value decreases, here, even if the volume setting value decreases, a visually impaired user can properly hear the guidance audio whose output volume value has been maintained within the specific range (constant value).

    [0086] Also, with the third reference example, the volume setting value Vd is a volume setting value at the midpoint (50 level) of the settable volume range (from the 0 level to the 100 level). Consequently, over the range of less than or equal to the midpoint (50 level) out of the settable volume range (from the 0 level to the 100 level), the output volume value of the guidance audio can be maintained within a specific range (constant value) even if the volume setting value is decreased. Thus, a visually impaired user can easily hear the guidance audio whose output volume value has been maintained within the specific range (constant value). Also, within a range in which the volume setting value is greater than the midpoint (from greater than the 50 level to the 100 level), the user can properly hear both the guidance audio and the non-guidance audio indicating audio related to video.

    [0087] Also, with the third reference example, over the range from the volume setting value Vd to the maximum volume setting value (100 level), the output volume value of the guidance audio and the output volume value of the non-guidance audio at the volume setting value Vd are substantially equal values. Consequently, over the range from the volume setting value Vd to the maximum volume setting value (100 level), the output volume value of the guidance audio is kept from going too high, while this guidance audio can be outputted at the proper output volume value. The rest of the effect of the third reference example is the same as that of the first reference example above.

    FOURTH REFERENCE EXAMPLE



    [0088] The configuration of a display device 400 pertaining to the fourth reference example will now be described through reference to FIGS. 1 and 5. In the first reference example, the output volume value of the guidance audio is increased when the volume setting value is increased over the entire range over which the volume setting value can be varied. On the other hand, in this fourth reference example, even if the volume setting value is increased, the guidance audio will be outputted at an output volume value W (constant value) that is greater than the 0 level. Except for a difference in the output volume value table, the device configuration in the fourth reference example is substantially the same as the device configuration in the first reference example above.

    [0089] As shown in FIG. 1, an output volume value table T4 is stored in a memory area (storage component) 440 of an audio output processor 414. In the fourth reference example, the audio output processor 414 performs control to output the guidance audio at an output volume value that is greater than the 0 level, based on the output volume value table T4. That is, as shown in FIG. 5, the audio output processor 414 performs audio output control using the output volume value table T4 set so that the output volume value of the guidance audio will not drop to the 0 level. The audio output processor 414 is an example of the "controller" of the present disclosure. The output volume value table T4 is an example of the "table" of the present disclosure.

    [0090] In the fourth reference example, the audio output processor 414 performs control to output the guidance audio at the constant output volume value W (such as the 70 level) when the volume setting value is increased over the entire range over which the volume setting value can be varied. In this case, the settable volume range of the setting component 51 of the remote control 50 (see FIG. 1) is set to a range in which the output volume value W of the guidance audio is greater than or equal to the output volume value of the non-guidance audio. Specifically, audio output control is performed so that over the range from the 0 level to the 100 level, the output volume value W of the guidance audio will always be greater than or equal to the output volume value of the non-guidance audio. Also, the audio output processor 414 performs audio output control so that when the volume setting value has reached the 100 level (maximum value), the output volume value of the non-guidance audio (the plot indicated by a broken line) is substantially equal to the output volume value W of the guidance audio (the plot indicated by a solid line).

    [0091] As discussed above, in the fourth reference example, control is performed so that the output volume value of the guidance audio will be the constant output volume value W (fixed value) over the entire range over which the volume setting value can be varied. The rest of the configuration in the fourth reference example is the same as that in the first reference example above.

    Effect of Fourth Reference Example



    [0092] The following effect can be obtained with the fourth reference example.

    [0093] With the fourth reference example, the audio output processor 414 is provided to set the output volume value of the guidance audio to be greater than the 0 level when the output volume value of the non-guidance audio is at the 0 level (a muted state), and to set the output volume value of the guidance audio to at least the output volume value of the non-guidance audio when the output volume value of the non-guidance audio is something other than the 0 level. Consequently, just as in the first reference example above, even when the volume setting value of the display device 400 has been set to the 0 level (a muted state), a visually impaired user can be reliably apprised of the content of the the guidance by means of the guidance audio at an output volume value that is greater than the 0 level.

    [0094] Also, with the fourth reference example, over the entire settable range of volume setting values, the output volume value W of the guidance audio is set to fall within a specific range (such as a constant value of "70 level"). Consequently, as long as the output volume value W of the guidance audio is set to the proper value in advance, a visually impaired user can hear the guidance audio at a uniform volume that allows the guidance to be clearly heard, no matter what the volume setting value is.

    [0095] Also, with the fourth reference example, the settable volume range of the setting component 51 of the remote control 50 can be set to a range in which the output volume value W of the guidance audio is greater than or equal to the output volume value of the non-guidance audio. Consequently, no matter what the volume setting value is within the settable volume range of the setting component 51, the output volume value W of the guidance audio can be set to be greater than or equal to the output volume value of the non-guidance audio. Thus, a visually impaired user can reliably hear the guidance audio while the non-guidance audio is being outputted. The rest of the effect of the fourth reference example is the same as that of the first reference example above.

    EMBODIMENT



    [0096] The configuration of a display device 401 pertaining to an embodiment of the present invention will now be described through reference to FIGS. 1 and 6. In the fourth reference example, the output volume value W of the guidance audio is fixed at a constant value (70 level). With this embodiment, the configuration allows the output volume value W to be varied.

    [0097] An output volume value table T4a is stored in the memory area 440 of the audio output processor 414 of the display device 401 (see FIG. 1). The audio output processor 414 performs control to output the guidance audio at an output volume value W that is greater than the 0 level, based on the output volume value table T4a. In this case, as shown in FIG. 6, the output volume value W written to the output volume value table T4a can be changed by the user to the desired values. For instance, if the output volume value W of the guidance audio has been set to the 30 level (the two-dot chain line plot), then the settable volume range of the setting component 51 of the remote control 50 (see FIG. 1) is changed to a range up to a volume setting value Ve1 corresponding to an intersection P1 with the output volume value of the non-guidance audio (the plot indicated by a broken line (fixed characteristics)) (from the 0 level to the Ve1 level). Similarly, if the output volume value W has been set to the 50 level, the 70 level, or the 90 level, then the settable volume range of the setting component 51 is changed to a range from the 0 level up to a volume setting value Ve2, Ve3, or the 100 level corresponding to intersections P2, P3, and P4 with the output volume value of the non-guidance audio. Thus, the settings are rewritten to the output volume value table T4a so that volume setting (horizontal axis of the graph in FIG. 6) is restricted to one of the ranges between the 0 level and the 100 level, over a range in which the output volume value of the non-guidance audio does not reach or exceed the output volume value W of the guidance audio, according to a change in the output volume value W of the guidance audio. The output volume value table T4a is an example of the "table" of the present disclosure. The rest of the configuration of the embodiment is the same as that in the fourth reference example above.

    Effect of Embodiment



    [0098] With the embodiment, the volume setting value (Ve) for the display device 401 can be adjusted to one of the ranges between the 0 level and the 100 level, over the range in which the output volume value of the non-guidance audio does not go over the output volume value W of the guidance audio, according to a change in the output volume value W of the guidance audio. Consequently, regardless of the volume of the guidance audio (the output volume value W), the output volume value of the non-guidance audio can be kept at or under the output volume value W of the guidance audio. Thus, a visually impaired user can easily hear the guidance audio no matter what the volume is. The rest of the effect of the embodiment is the same as that of the first reference example above.

    MODIFICATION EXAMPLE OF FOURTH REFERENCE EXAMPLE



    [0099] The configuration of a display device 402 pertaining to a modification example of the fourth reference example will now be described through reference to FIGS. 1 and 7. In the embodiment, the characteristics of the output volume value of the non-guidance audio are fixed regardless of the setting of the output volume value W of the guidance audio. With this modification example of the fourth reference example, the configuration allows the output volume value of the non-guidance audio to be varied according to the setting of the output volume value W of the guidance audio.

    [0100] An output volume value table T4b is stored in the memory area 440 of the audio output processor 414 of the display device 402 (see FIG. 1). The audio output processor 414 performs control to output the guidance audio at an output volume value W that is greater than the 0 level, based on the output volume value table T4b. In this case, as shown in FIG. 7, the output volume values W written to the output volume value table T4b can be changed by the user to the desired values. The configuration is such that the characteristics of the output volume value of the non-guidance audio are also changed according to the setting (changed value) of the output volume value W of the guidance audio.

    [0101] For instance, if the output volume value W of the guidance audio has been set to the 70 level (the two-dot chain line plot), then the settings in the output volume value table T4b are determined so that the output volume value of the non-guidance audio will have the characteristics G1. Also, the configuration is such that if the output volume value W is set to the 30 level (two-dot chain line plot) or the 90 level (two-dot chain line plot), the settings in the output volume value table T4b are rewritten so that the output volume value of the non-guidance audio will have the characteristics G2 or the characteristics G3. Furthermore, no matter what output volume value W the guidance audio is set to, the characteristics of the output volume value of the non-guidance audio will be changed, and the user will be permitted to adjust the volume setting value of the display device 402 up to the maximum level of 100 (from the 0 level to the 100 level). Thus, even if the output volume value W of the guidance audio is changed, the characteristics (such as G1 to G3) of the output volume value of the non-guidance audio will be changed according to the change of the output volume value W of the guidance audio, and the setting will be rewritten in the output volume value table T4b so that the maximum volume setting value (the horizontal axis in the graph in FIG. 7) is permitted up to the 100 level. The output volume value table T4b is also an example of the "table" of the present disclosure. The rest of the configuration of the modification example of the fourth reference example is the same as that of the fourth reference example above.

    Effect of Modification Example of Fourth Reference Example



    [0102] With the modification example of the fourth reference example, the characteristics (such as G1 to G3) of the output volume value of the non-guidance audio are changed according to a change in the output volume value W of the guidance audio. The maximum volume setting value is always permitted up to the 100 level. Consequently, regardless of the volume (the output volume value W) of the guidance audio, the user can set the volume of the display device 402 between the 0 level and the 100 level (the maximum setting value). Specifically, no matter what the output volume value W (constant value) of the guidance audio is, the user can set the display device 402 to a comfortable volume by effectively using the widest volume setting range (from the 0 level to the 100 level). The rest of the effect of the modification example of the fourth reference example is the same as that of the first reference example above.

    FIFTH REFERENCE EXAMPLE



    [0103] The configuration of a display device 500 pertaining to the fifth reference example will now be described through reference to FIGS. 1 to 5. In the first reference example, audio output processing is performed using a single output volume value table in which output volume values for the non-guidance audio and output volume values for the guidance audio are associated with volume setting values. With this fifth reference example, a plurality of output volume value tables are stored. The audio output processing is performed using the most suitable output volume value table according to the guidance content. Except for a difference in the number of output volume value tables stored in the memory area 540, the device configuration in the fifth reference example is substantially the same as the device configuration in the first reference example above.

    [0104] With the fifth reference example, a plurality of (four in this reference example) different output volume value tables are stored in the memory area (storage component) 540 of the audio output processor 514 (see FIG. 1), for example. More precisely, the memory area (storage component) 540 stores the output volume value table T1 (see FIG. 2) as a first table, and the output volume value table T2 (see FIG. 3) as a second table. In the output volume value table T2, output volume values different from the output volume values of the guidance audio in the output volume value table T1 are associated as the output volume values for the guidance audio with volume setting values. The memory area (storage component) 540 further stores the output volume value table T3 (see FIG. 4), which is different from the output volume value tables T1 and T2, and the output volume value table T4 (see FIG. 5), which is different from the output volume value tables T1 to T3. Of course, different number of output volume value tables can be stored in the memory area 540.

    [0105] The audio output processor 514 switches between the output volume value tables T1 to T4 according to the guidance content (performs control based on one of the output volume value tables), and thereby making the output volume value of the non-guidance audio different from the output volume value of the guidance audio. The audio output processor 514 is an example of the "controller" of the present disclosure.

    [0106] For example, when giving a notification without which the convenience of a visually impaired user would be compromised (when outputting information related to channel changing as the guidance information, for example), the audio output processor 514 selects from among the output volume value tables T1 to T4 the output volume value table with which the guidance audio can be outputted at the highest volume at the current volume setting value, and performs control processing based on the selected output volume value table.

    [0107] Also, for example, when giving a notification without which the convenience of a visually impaired user would not be compromised (a notification whose omission would pose no special inconvenience to a visually impaired user), the audio output processor 514 selects from among the output volume value tables T1 to T4 one output volume value table with which the guidance audio can be outputted at the second-highest volume at the current volume setting value, and performs control processing based on the selected output volume value table. The rest of the configuration of the fifth reference example is the same as in the first reference example above.

    Effect of Fifth Reference Example



    [0108] The following effect can be obtained with the fifth reference example.

    [0109] With the fifth reference example, the audio output processor 514 is provided to set the output volume value of the guidance audio to be greater than the 0 level when the output volume value of the non-guidance audio is at the 0 level (a muted state), and to set the output volume value of the guidance audio to at least the output volume value of the non-guidance audio when the output volume value of the non-guidance audio is something other than the 0 level. Consequently, just as in the first reference example above, even when the volume setting value of the display device 500 has been set to the 0 level (a muted state), a visually impaired user can be reliably apprised of the content of the guidance by means of the guidance audio at an output volume value that is greater than the 0 level.

    [0110] Also, with the fifth reference example, the audio output processor 514 performs control over the output volume value of the guidance audio by switching between the output volume value tables T1 to T4 according to the content of the guidance. Consequently, the output volume value of the guidance audio can be set to a more suitable output volume value according to the content of the guidance audio by switching between the output volume value tables T1 to T4. For example, even when giving a notification without which the convenience of a visually impaired user would be compromised (when outputting information related to channel changing as the guidance information, for example), the guidance audio can be reliably conveyed. The rest of the effect of the fifth reference example is the same as in the first reference example above.

    OTHER MODIFICATION EXAMPLES



    [0111] The reference examples and the embodiment disclosed herein are illustrative in all respects, and should not be construed as being limiting in nature. The scope of the invention is indicated by the appended claims.

    [0112] For instance, in the first to fifth reference examples and the embodiment above, the display devices 100 to 500 are all television sets, but the present invention is not limited to this. The display devices 100 to 500 can instead be something other than a television set, such as a tablet or personal computer.

    [0113] Also, in the first to fifth reference examples and the embodiment above, an example is given of performing audio output processing using the output volume value tables T1 to T4, but the present invention is not limited to this. With the present invention, audio output processing can be performed without providing an output volume value table. For example, audio output processing can be performed by calculation using correlation (graph or function) illustrated in FIGS. 2 to 7.

    [0114] Also, in the first to fifth reference examples and the embodiment above, the setting component 51 of the remote control 50 is used to make changes to the volume setting value on the display devices 100 to 500, but the present invention is not limited to this. With the present invention, changes to the volume setting value can be made via a setting component provided to the main body (the housing) of the display devices 100 to 500.

    [0115] Also, in the fifth reference example above, the four output volume value tables T1 to T4 are stored, but the present invention is not limited to this. With the present invention, a plurality of output volume values tables can be stored in some number other than four.

    [0116] Also, in the first to third and fifth reference examples above, the output volume of the guidance audio corresponding to at least a partial range of the volume setting values varied linearly, but the present invention is not limited to this. With the present invention, the output volume of the guidance audio can be varied non-linearly.

    [0117] Also, in the first to fourth reference examples and the embodiment above, control is performed using the various output volume value tables T1 to T4, and in the fifth reference example above, control is performed by selecting one of the output volume value tables T1 to T4, but the present invention is not limited to this. With the present invention, some other output volume value table besides the output volume value tables T1 to T4 can be used. For instance, an output volume value table in which there are portions at two locations where the output volume value is constant, as in the modification example of the present invention shown in FIG. 8. In this case, a constant output volume value F1 is used in a range in which the volume setting value is less than a specific volume setting value Vf1 (a range from the 0 level to Vf1), while a constant output volume value F2 is used in a range in which the volume setting value is greater than a specific volume setting value Vf2 (a range from Vf2 to the maximum value). Also, there is a linear change in volume setting values in between these (a range from Vf1 to less than Vf2).

    [0118] Also, in the first to fifth reference examples and the embodiment above, the "output volume value" outputted from the output component 4 is directly ascertained as the volume adjustment amount in a range from the 0 level (0%) to the 100 level (100%), and the output volume value tables T1 to T4 are provided for setting these volumes, but the present invention is not limited to this. As to how the "output volume value" defined by the output volume value tables T1 to T4 is viewed, the product of multiplying the "input audio data" inputted from outside to the display device 100 by a specific amplification ratio A with the amplifier 3 is further multiplied by the above-mentioned audio adjustment amount (0% to 100%) to give an "output volume value." With this configuration, the the display device can also be configured such that when the volume setting is set such that the volume of the "second signal" of the present invention is a first volume that is lower than a specific volume, the volume of the "first audio" will be greater than this first volume. Also, as another configuration example, the present invention can also be applied to a configuration in which the "output volume value" outputted from the output component 4 is obtained by multiplying a volume adjustment amplification ratio B (a numerical value in the range of -∞ to +α) by the "input audio data" inputted from the outside.

    [0119] Also, in the first to fifth reference examples and the embodiment above, an example of the guidance audio includes the information related to operations performed on the display device 100 using the remote control 50 or the information related to the status of the display device 100, but the present invention is not limited to this. The "first audio" in the present invention can be something such as "the volume is xxx" or "the volume is set to the maximum (minimum)" when the user changes the volume from the speaker 9. Also, the "first audio" in the present invention can be something such as "channel xxx" when the user changes the channel number. In this case, the channel number can be pronounced, or the broadcast station acquired from an EPG via the receiver 6 can be pronounced. Also, the "first audio" in the present invention can be something such as "HDMI™ xxx (number)" or "video input" when the external input to the display device 100 is switched. Furthermore, a case in which menu selection is performed is assumed as part of the operations performed by the user on the display device 100. In this case, the audio content can be something such as "screen setting menu" or "audio setting menu", to let the user know the menu category that is currently selected with the cursor on the menu screen. All of these are encompassed by the guidance audio.

    [0120] Also, in the first to fifth reference examples and the embodiment above, the output volume value of the guidance audio is usually set to be greater than the 0 level when the output volume value of the non-guidance audio is at the 0 level, and the output volume value of the guidance audio is set to be greater than or equal to the output volume value of the non-guidance audio when the output volume value of the non-guidance audio is something other than the 0 level, but the present invention is not limited to this. For example, depending on the user's preference, the display devices 100 to 500 can be configured to allow the user to temporarily change the setting of audio output processing so that the characteristics of the output volume value of the guidance audio and the characteristics of the output volume value of the non-guidance audio will be reversed (inverted) from what is given above. The configuration can also be such that it is possible to return to the original settings when a visually impaired user uses the display devices 100 to 500.

    [0121] In understanding the scope of the present invention, the term "comprising" and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, "including", "having" and their derivatives. Also, the terms "part," "section," "portion," "member" or "element" when used in the singular can have the dual meaning of a single part or a plurality of parts unless otherwise stated.

    [0122] While only selected reference examples and an embodiment have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, unless specifically stated otherwise, the size, shape, location or orientation of the various components can be changed as needed and/or desired so long as the changes do not substantially affect their intended function. Unless specifically stated otherwise, components that are shown directly connected or contacting each other can have intermediate structures disposed between them so long as the changes do not substantially affect their intended function. The functions of one element can be performed by two, and vice versa unless specifically stated otherwise. The structures and functions of one reference example or embodiment can be adopted in another reference example or embodiment. It is not necessary for all advantages to be present in a particular reference example or embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions of the reference examples and the embodiment according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims.


    Claims

    1. A display device (100) comprising:

    a display component (2);

    an output component (4) configured to output a first signal having guidance information and a second signal having audio information as guidance audio and non-guidance audio, respectively, the guidance information pertaining to an operation performed on the display device or a status of the display device, the audio information pertaining to content displayed on the display component (2);

    a setting component (51) configured to perform volume setting;

    a table in which an output level of the first signal and output levels of the second signal are respectively associated with volume setting values, the output level of the first signal being an output volume value of the first signal, the output levels of the second signal being output volume values of the second signal; and

    a controller (14) configured to control output levels of the first signal and the second signal based on the table,

    characterized in that:

    the table is configured such that the output level of the first signal written to the table can be changed by a user to a desired value; and

    the table is further configured to be rewritten according to a change in the written output level of the first signal such that the volume setting value of the display device is restricted to a range in which the output level of the second signal does not reach nor exceed the output level of the first signal, such that the controller sets the output level of the first signal to a value that is greater than the output level of the second signal and sets the output level of the first signal to a value greater than zero when the output level of the second signal is zero.


     
    2. The display device (100) according to claim 1, wherein
    difference between the output level of the first signal and the output level of the second signal at a specific volume setting value is greater than difference between the output level of the first signal and the output level of the second signal at another volume setting value that is greater than the specific volume setting value.
     
    3. The display device (100) according to claim 1 or 2, wherein
    the output level of the first signal is a value that falls within a specific range.
     


    Ansprüche

    1. Anzeigevorrichtung (100) mit:

    einer Anzeigekomponente (2);

    einer Ausgabekomponente (4), die konfiguriert ist, ein erstes Signal mit Führungsinformationen und ein zweites Signal auszugeben, die Audioinformationen als Führungsaudio bzw. als Nicht-Führungsaudio aufweisen, wobei die Führungsinformationen eine Operation, die auf der Anzeigevorrichtung ausgeführt wird, oder einen Status der Anzeigevorrichtung betreffen, wobei die Audioinformationen einen Inhalt betreffen, der auf der Anzeigekomponente (2) angezeigt wird;

    einer Einstellkomponente (51), die konfiguriert ist, eine Lautstärkeeinstellung durchzuführen;

    einer Tabelle, in der ein Ausgangspegel des ersten Signals und Ausgangspegel des zweiten Signals jeweils mit Lautstärkeeinstellwerten verknüpft sind, wobei der Ausgangspegel des ersten Signals ein Ausgangslautstärkewert des ersten Signals ist und die Ausgangspegel des zweiten Signals Ausgangslautstärkewerte des zweiten Signals sind;

    und

    einer Steuereinrichtung (14), die konfiguriert ist, Ausgangspegel des ersten Signals und des zweiten Signals beruhend auf der Tabelle zu steuern,

    dadurch gekennzeichnet, dass:

    die Tabelle so konfiguriert ist, dass der in die Tabelle geschriebene Ausgangspegel des ersten Signals durch einen Benutzer auf einen erwünschten Wert geändert werden kann; und

    die Tabelle ferner konfiguriert ist, entsprechend einer Änderung des geschriebenen Ausgangspegels des ersten Signals so neu geschrieben zu werden, dass der Lautstärkeeinstellwert der Anzeigevorrichtung auf einen Bereich beschränkt wird, in dem der Ausgangspegel des zweiten Signals den Ausgangspegel des ersten Signals weder erreicht noch überschreitet, so dass die Steuereinrichtung den Ausgangspegel des ersten Signals auf einen Wert einstellt, der größer als der Ausgangspegel des zweiten Signals ist, und den Ausgangspegel des ersten Signals auf einen Wert einstellt, der größer als Null ist, wenn der Ausgangspegel des zweiten Signals Null ist.


     
    2. Anzeigevorrichtung (100) nach Anspruch 1, wobei eine Differenz zwischen dem Ausgangspegel des ersten Signals und dem Ausgangspegel des zweiten Signals bei einem spezifischen Lautstärkeeinstellwert größer als eine Differenz zwischen dem Ausgangspegel des ersten Signals und dem Ausgangspegel des zweiten Signals bei einem anderen Lautstärkeeinstellwert ist, der größer als der spezifische Lautstärkeeinstellwert ist.
     
    3. Anzeigevorrichtung (100) nach Anspruch 1 oder 2, wobei der Ausgangspegel des ersten Signals ein Wert ist, der in einen spezifischen Bereich fällt.
     


    Revendications

    1. Dispositif d'affichage (100), comprenant :

    un composant d'affichage (2) ;

    un composant de sortie (4) prévu pour émettre un premier signal comprenant des informations de guidage et un deuxième signal comprenant des informations audio respectivement en tant qu'audio de guidage et audio de nonguidage, les informations de guidage relevant d'une opération effectuée sur le dispositif d'affichage ou d'un état du dispositif d'affichage, les informations audio relevant d'un contenu affiché sur le composant d'affichage (2) ;

    un composant de réglage (51) prévu pour effectuer un réglage de volume ;

    une table où un niveau de sortie du premier signal et des niveaux de sortie du deuxième signal sont respectivement associées à des valeurs de réglage de volume, le niveau de sortie du premier signal étant une valeur de volume de sortie du premier signal, les niveaux de sortie du deuxième signal étant des valeurs de volume de sortie du deuxième signal ; et

    un contrôleur (14) prévu pour commander des niveaux de sortie du premier signal et du deuxième signal sur la base de la table,

    caractérisé en ce que :

    la table est prévue de telle manière que le niveau de sortie du premier signal porte dans la table peut être modifié par un utilisateur à une valeur souhaitée ; et

    la table est en outre prévue pour être réécrite en fonction d'une modification dans le niveau de sortie écrit du premier signal, de manière à restreindre la valeur de réglage de volume du dispositif d'affichage dans une plage où le niveau de sortie du deuxième signal n'atteint ni ne dépasse le niveau de sortie du premier signal, de sorte que le contrôleur règle le niveau de sortie du premier signal à une valeur supérieure au niveau de sortie du deuxième signal et règle le niveau de sortie du premier signal à une valeur supérieure à zéro si le niveau de sortie du deuxième signal est zéro.


     
    2. Dispositif d'affichage (100) selon la revendication 1, où la différence entre le niveau de sortie du premier signal et le niveau de sortie du deuxième signal à une valeur de réglage de volume spécifique est supérieure à la différence entre le niveau de sortie du premier signal et le niveau de sortie du deuxième signal à une autre valeur de réglage de volume, supérieure à la valeur de réglage de volume spécifique.
     
    3. Dispositif d'affichage (100) selon la revendication 1 ou la revendication 2, où
    le niveau de sortie du premier signal est une valeur située dans une plage spécifique.
     




    Drawing





























    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description