BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to a broadcast receiving apparatus, a control method
therefor, and a control program therefor. More particularly, the invention relates
to a broadcast receiving apparatus for identifying the broadcast station name based
on data received from the broadcast station, a control method therefor, and a control
program therefor.
2. Description of the Related Art
[0002] As disclosed in International Publication No.
2012/073464, in Europe, frequency modulation (FM) radio broadcasting utilizes a protocol standard
called the radio data system (RDS) for transmitting broadcast waves carrying an audio
signal and a data signal multiplexed with each other. A broadcast receiving apparatus
demultiplexes broadcast waves into an audio signal and a data signal and then outputs
sound based on the audio signal and obtains various items of information based on
the data signal.
[0003] Examples of information transmitted by means of a data signal are program service
name (PS) information and radio text (RT) information. PS information is character
information constituted by a maximum of eight characters related to a broadcast station
name. According to the RDS standard, PS information only indicates the broadcast station
name. RT information is character information constituted by a maximum of 64 characters
indicating a program name, a title of a song, weather forecasts, advertisement, and
so on. In reality, however, according to the operation unique to a broadcast station,
a protocol standard called the dynamic PS system which allows information other than
the broadcast station name to be transmitted as PS information may be utilized. According
to the dynamic PS system, PS information includes part of RT information, for example.
[0004] According to the dynamic PS system, it is not possible to identify the broadcast
station name from PS information. In the broadcast receiving apparatus disclosed in
Japanese Unexamined Patent Application Publication No.
2014-127901, to identify the broadcast station name according to the dynamic PS system, the received
items of PS information are compared with broadcast station names stored in a storage
device of the broadcast receiving apparatus, and then, an item of PS information that
is found to match one of the stored broadcast station names is used as the broadcast
station name.
SUMMARY OF THE INVENTION
[0005] In the method disclosed in this publication, however, it is necessary to store all
the existing broadcast station names. Thus, an enormous amount of data space is required
in the storage device, comparing of PS information with broadcast station names is
time-consuming, and updating of a broadcast station name is not supported.
[0006] In view of this background, the present invention provides a broadcast receiving
apparatus which allows the broadcast station name to be speedily identified with a
small storage capacity, a control method therefor, and a control program therefor.
[0007] According to an aspect of the invention, there is provided a broadcast receiving
apparatus (100) for receiving broadcast waves. The broadcast waves carry a data signal
and an audio signal multiplexed with each other. The data signal is capable of transmitting
first character information and second character information. The first character
information is used for transmitting a broadcast station name. The second character
information includes character information other than the broadcast station name.
The broadcast receiving apparatus (100) includes a receiver (110), a data signal obtaining
unit (141), a character information obtaining unit (143), and a broadcast station
name identifying unit (144). The receiver (110) receives the broadcast waves transmitted
from the broadcast station. The data signal obtaining unit (141) obtains the data
signal from the received broadcast waves. The character information obtaining unit
(143) obtains the first character information and the second character information
from the obtained data signal. The broadcast station name identifying unit (144) identifies
the broadcast station name, based on a comparison result of comparing the first character
information with the second character information.
[0008] The above-described configuration eliminates the need to store all broadcast station
names and to compare the first character information with all the broadcast station
names. It is thus possible to speedily identify a broadcast station name with a small
storage capacity.
[0009] Preferably, in the broadcast receiving apparatus (100), the broadcast station name
identifying unit (144) may extract one or more candidate character strings appearing
at least one time as the first character information from among a plurality of items
of the first character information obtained at different times. The broadcast station
name identifying unit (144) may obtain the comparison result of comparing the first
character information with the second character information indirectly by comparing
the candidate character strings with the second character information. The broadcast
station name identifying unit (144) may determine, based on the comparison result
of comparing the first character information with the second character information,
whether or not there is only one candidate character string that is not included in
the second character information. If it is determined that there is only one candidate
character string that is not included in the second character information, the broadcast
station name identifying unit (144) may identify the candidate character string that
is not included in the second character information as the broadcast station name.
[0010] This configuration makes it possible to precisely identify the broadcast station
name by excluding candidate character strings included in the second character information
that are unlikely to be the broadcast station name.
[0011] Preferably, in the broadcast receiving apparatus (100), the broadcast station name
identifying unit (144) may count, as appearance frequency, how many times each of
the candidate character strings appears among the plurality of items of the first
character information. The broadcast station name identifying unit (144) may identify
the broadcast station name further based on the appearance frequency.
[0012] This configuration makes it possible to identify the broadcast station name further
precisely, based on the assumption that the first character information used for transmitting
the broadcast station name is highly likely to be the broadcast station name.
[0013] Preferably, in the broadcast receiving apparatus (100), if it is determined that
there is not only one candidate character string that is not included in the second
character information, and that there is only one candidate character string that
appears most frequently among the candidate character strings that are not included
in the second character information, the broadcast station name identifying unit (144)
identifies the candidate character string that appears most frequently as the broadcast
station name.
[0014] This configuration makes it possible to identify the broadcast station name further
precisely, based on the appearance frequency in addition to the comparison result
of comparing the first character information with the second character information.
[0015] Preferably, in the broadcast receiving apparatus (100), the broadcast station name
identifying unit (144) may identify the broadcast station name further based on a
comparison result of comparing the first character information with at least one of
predetermined keywords.
[0016] This configuration makes it possible to identify the broadcast station name further
precisely by preparing some keywords that are highly likely to be used for the broadcast
station names as the predetermined keywords.
[0017] Preferably, in the broadcast receiving apparatus (100), if it is determined that
there is not only one candidate character string that is not included in the second
character information, that there is not only one candidate character string that
appears most frequently among the candidate character strings that are not included
in the second character information, and that there is only one candidate character
string that includes at least one of the predetermined keywords among the candidate
character strings that appear most frequently, the broadcast station name identifying
unit (144) may identify the candidate character string that includes at least one
of the predetermined keywords as the broadcast station name.
[0018] This configuration makes it possible to identify the broadcast station name further
precisely, based on the comparison result of comparing the first character information
with the predetermined keywords in addition to the appearance frequency and the comparison
result of comparing the first character information with the second character information.
[0019] Preferably, in the broadcast receiving apparatus (100), the broadcast station name
identifying unit (144) may start identifying the broadcast station name upon detecting
that a plurality of items of the first character information obtained at different
times are different from each other.
[0020] This configuration makes it possible to precisely identify the broadcast station
name when it is likely that the first character information has been transmitted according
to the dynamic PS system.
[0021] According to an aspect of the invention, there is provided a control method for a
broadcast receiving apparatus (100). The broadcast receiving apparatus (100) receives
broadcast waves. The broadcast waves carry a data signal and an audio signal multiplexed
with each other. The data signal is capable of transmitting first character information
and second character information. The first character information is used for transmitting
a broadcast station name. The second character information includes character information
other than the broadcast station name. The control method includes: a step (171) of
receiving the broadcast waves transmitted from the broadcast station; a step (172)
of obtaining the data signal from the received broadcast waves; a step (173) of obtaining
the first character information and the second character information from the obtained
data signal; and a step (186, 189, 192) of identifying the broadcast station name,
based on a comparison result of comparing the first character information with the
second character information.
[0022] According to an aspect of the invention, there is provided a control program for
a broadcast receiving apparatus (100). The control program causes a computer to execute
the above-described control method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023]
Fig. 1 is a block diagram illustrating a broadcast receiving apparatus according to
an embodiment of the invention;
Fig. 2 is a flowchart illustrating a first control method performed by the broadcast
receiving apparatus shown in Fig. 1;
Fig. 3 illustrates an example of a first character information table stored in a storage
device of the broadcast receiving apparatus shown in Fig. 1;
Fig. 4 illustrates an example of a second character information table stored in the
storage device;
Fig. 5 is a flowchart illustrating a second control method performed by the broadcast
receiving apparatus shown in Fig. 1;
Fig. 6 illustrates a first decision table created by a broadcast station name identifying
unit of the broadcast receiving apparatus shown in Fig. 1;
Fig. 7 illustrates a second decision table created by the broadcast station name identifying
unit;
Fig. 8 illustrates a third decision table created by the broadcast station name identifying
unit;
Fig. 9 illustrates a fourth decision table created by the broadcast station name identifying
unit; and
Fig. 10 illustrates a fifth decision table created by the broadcast station name identifying
unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
(Description of Overall Embodiment)
[0024] A broadcast receiving apparatus 100 according to an embodiment of the invention will
be described below. Fig. 1 is a block diagram illustrating the broadcast receiving
apparatus 100. A broadcast station, which is not shown, transmits FM radio broadcast
waves carrying an audio signal and a data signal multiplexed with each other according
to the RDS standard in Europe. The broadcast receiving apparatus 100 receives the
broadcast waves and then plays back sound from the audio signal and also obtains character
information from the data signal.
[0025] The broadcast station transmits PS information and RT information by means of the
data signal. The data signal also indicates other items of information. Character
information transmitted by means of the data signal may be transmitted at one time
together or may be divided and transmitted at different times.
[0026] PS information is character information based on the RDS standard and constituted
by a maximum of eight characters for transmitting a broadcast station name. PS information
is transmitted regularly, for example. The content of PS information is fixed in some
cases and changes over time in other cases. PS information may be character information
constituted by more than or less than eight characters at a maximum. In this specification,
PS information may also be called first character information.
[0027] RT information is character information based on the RDS standard and constituted
by a maximum of 64 characters representing a program name, a title of a song, weather
forecasts, advertisement, and so on. RT information is transmitted regularly, for
example. The content of RT information is fixed in some cases and changes over time
in other cases. RT information may be character information constituted by more than
or less than 64 characters at a maximum. Although RT information is character information
mainly representing information other than the broadcast station name, it may indicate
the broadcast station name in some cases. In this specification, RT information may
also be called second character information.
[0028] According to the RDS standard, PS information only indicates the broadcast station
name. In reality, however, according to the operation unique to a broadcast station,
a protocol standard called the dynamic PS system which allows information other than
the broadcast station name to be transmitted as PS information may be utilized. According
to the dynamic PS system, PS information includes part of RT information, for example.
(Configuration of Broadcast Receiving Apparatus)
[0029] The broadcast receiving apparatus 100 includes a receiver 110, an operation unit
120, a storage device 130, a controller 140, an audio signal processing device 150,
and a display device 160. The receiver 110 receives broadcast waves. The operation
unit 120 receives input operations from an operator. The controller 140 extracts an
audio signal and a data signal from broadcast waves and executes processing, which
will be discussed below. The audio signal processing device 150 plays back the audio
signal output from the controller 140. The display device 160 displays characters
in accordance with an instruction from the controller 140. The broadcast receiving
apparatus 100 demultiplexes broadcast waves into an audio signal and a data signal,
and then outputs sound based on the audio signal and obtains various items of information
based on the data signal.
[0030] The receiver 110 includes an antenna which can receive FM radio broadcast waves.
Broadcast waves received by the receiver 110 are sent to the controller 140 in the
state in which an audio signal and a data signal are multiplexed in the broadcast
waves.
[0031] The operation unit 120 includes various buttons which receive various input operations
from an operator. Examples of the buttons are an ON/OFF button for turning ON and
OFF the main power of the broadcast receiving apparatus 100, a channel selection button
for receiving the selection of a broadcast station from an operator, and a volume
button for adjusting the volume of output sound. Such buttons are not shown. The operation
unit 120 may be constituted by buttons other than those described in this embodiment.
The operation unit 120 may be another type of operation unit other than buttons, such
as a touch panel or a dial.
[0032] The storage device 130 includes a control program 131. The control program 131 is
read by an operation processor 142 of the controller 140, which will be discussed
later in detail. The control program 131 causes the operation processor 142 to implement
the function of performing a first control method and part of a second control method
and other functions. While the operation processor 142 is executing various functions,
the storage device 130 stores various items of information including PS information
and RT information under the control of the operation processor 142. The storage device
130 is a non-transitory tangible storage medium. The storage device 130 is a volatile
or non-volatile storage medium including a read only memory (ROM) and a random access
memory (RAM). The storage device 130 may be removable or may be fixed.
[0033] The controller 140 includes a data signal obtaining unit 141 and the operation processor
142. In the controller 140 of this embodiment, the data signal obtaining unit 141
is constituted by an application specific integrated circuit (ASIC), while the operation
processor 142 is constituted by a general-purpose computer. Alternatively, the controller
140 may be a general-purpose computer or another circuit which can implement the functions
discussed in this embodiment. The operation processor 142 may be an ASIC or another
circuit which can implement the functions discussed in this embodiment.
[0034] The data signal obtaining unit 141 demultiplexes broadcast waves received from the
receiver 110 into an audio signal and a data signal. The data signal obtaining unit
141 sends the audio signal to the audio signal processing device 150 and the data
signal to the operation processor 142.
[0035] The operation processor 142 functions as a character information obtaining unit 143
and a broadcast station name identifying unit 144 as a result of reading the control
program 131 stored in the storage device 130 and executing the control program 131.
[0036] The character information obtaining unit 143 obtains the first character information
(that is, PS information) and the second character information (that is, RT information)
from a data signal, as in a manner similar to the related art. The character information
obtaining unit 143 may obtain character information other than the first character
information and the second character information. The character information obtaining
unit 143 also stores ten items of the first character information that have been received
most recently and one item of the second character information that has been received
most recently in the storage device 130. The character information obtaining unit
143 may store more than or less than ten items of the first character information
and/or may store plurality of items of the second character information.
[0037] The broadcast station name identifying unit 144 identifies the broadcast station
name that has transmitted the broadcast waves received by the receiver 110, based
on the comparison result of comparing the first character information with the second
character information. This will be discussed later in detail.
[0038] The audio signal processing device 150 includes a speaker, for example, and plays
back sound based on the audio signal received from the data signal obtaining unit
141. The display device 160 includes a liquid crystal display, for example, and displays
the identified broadcast station name in response to an instruction from the broadcast
station name identifying unit 144. The display device 160 displays the obtained the
second character information at a suitable timing in response to an instruction from
the character information obtaining unit 143.
(First Control Method)
[0039] Fig. 2 is a flowchart illustrating a first control method performed by the broadcast
receiving apparatus 100 shown in Fig. 1. The first control method is a preparation
process prior to a process for identifying a broadcast station name. The first control
method will be described below with reference to Fig. 2. The first control method
is regularly executed in the state in which a broadcast station is being selected.
More specifically, the first control method is executed when the main power is turned
ON by the operation unit 120 or when the selection of the broadcast station is changed
by the operation unit 120.
[0040] In step 171, the receiver 110 starts receiving broadcast waves.
[0041] Then, in step 172, the data signal obtaining unit 141 obtains a data signal from
the broadcast waves received by the receiver 110 and sends the data signal to the
operation processor 142. The data signal obtaining unit 141 also obtains an audio
signal from the broadcast waves received by the receiver 110 and sends the audio signal
to the audio signal processing device 150.
[0042] Then, in step 173, if at least one of the first character information and the second
character information is included in the data signal obtained by the data signal obtaining
unit 141, the character information obtaining unit 143 stores the first character
information and/or the second character information included in the data signal in
the storage device 130.
[0043] Fig. 3 illustrates an example of a first character information table 210 storing
the first character information. The first character information table 210 stores
ten items of the first character information 211-1 through 211-10. Hereinafter, the
ten items of the first character information 211-1 through 211-10 may simply be called
the first character information 211. If ten items of the first character information
211 are already stored, the oldest item of the first character information 211 is
replaced by the latest item of the first character information 211. Examples of the
first character information 211 are "ZZZZZ-FM", "AAAAAAAA", and "BBBBBBBB". Another
character string may be used as the first character information 211. The first character
information 211 may include a broadcast station name or may not include it.
[0044] Fig. 4 illustrates an example of a second character information table 220 storing
the second character information. The second character information table 220 stores
one item of the second character information 221. If the second character information
221 is already stored, this item of the second character information 221 is replaced
by a newer item of the second character information 221. An example of the second
character information 221 is a 64-character string constituted by eight 8-character
strings, that is, "AAAAAAAA", "BBBBBBBB", "CCCCCCCC", "DDDDDDDD", "EEEEEEEE", "FFFFFFFF",
"GGGGGGGG", and "HHHHHHHH", arranged in this order.
[0045] In this embodiment, for the sake of convenience, meaningless character strings are
described as the first character information 211 and the second character information
221. In reality, in most cases, meaningful characters, such as a broadcast station
name, a word, for example, "Hello", and a website address, are transmitted as the
first character information 211 or the second character information 221. The transmission
timing and the transmission frequency of the first character information and those
of the second character information may be the same or may be different at the discretion
of a broadcast station. For example, the first character information is transmitted
several times or several dozens of times during a period from when the second character
information is transmitted until when the next second character information is transmitted.
[0046] Referring back to Fig. 2, in step 174, the broadcast station name identifying unit
144 determines whether a predetermined condition is satisfied. An example of the predetermined
condition is that ten items of the first character information 211 (Fig. 3) are stored
and one item of the second character information 221 (Fig. 4) is stored. Another example
of the predetermined condition is that at least one of the ten stored items of the
first character information 211 is replaced by a new item of the first character information
211. Another example of the predetermined condition is that the stored item of the
second character information 221 is replaced by a new item of the second character
information 221.
[0047] If it is determined in step 174 that the predetermined condition is satisfied, the
first control method is completed. If it is determined in step 174 that the predetermined
condition is not satisfied, steps 172 through 174 are repeated.
(Second Control Method)
[0048] Fig. 5 is a flowchart illustrating a second control method performed by the broadcast
receiving apparatus 100 shown in Fig. 1. The broadcast receiving apparatus 100 identifies
the broadcast station name that has transmitted the broadcast waves received by the
receiver 110 by using the second control method. The second control method will be
described below with reference to Fig. 5. The second control method is executed after
the first control method shown in Fig. 2 has been completed, for example. At least
one item of the first character information 211 (Fig. 3) and/or the second character
information 221 (Fig. 4) may be replaced while the second control method is being
executed, for example.
[0049] A first decision table 230-1 shown in Fig. 6, a second decision table 230-2 shown
in Fig. 7, a third decision table 230-3 shown in Fig. 8, a fourth decision table 230-4
shown in Fig. 9, and a fifth decision table 230-5 shown in Fig. 10 are examples of
information created by the broadcast station name identifying unit 144 and stored
in the storage device 130 (Fig. 1) in the second control method. Hereinafter, the
first through fifth decision tables 230-1 through 230-5 may simply be called the decision
table 230.
[0050] For the sake of convenience, the decision table 230 shown in Fig. 7 is created based
on the first character information 211 shown in Fig. 3 and the second character information
221 shown in Fig. 4, and the decision tables 230 shown in Figs. 6, 8, 9, and 10 are
created based on the first character information and the second character information
obtained at different times from the first character information 211 shown in Fig.
3 and the second character information 221 shown in Fig. 4. The decision tables 230
shown in Figs. 6 through 10 are not necessarily based on the first character information
obtained from the same broadcast station, nor do they necessarily cover all the examples.
[0051] In step 181 in Fig. 5, the broadcast station name identifying unit 144 (Fig. 1) extracts
one or more candidate character strings that appear at least one time as the first
character information, from among the plurality of items of the first character information
obtained at different times.
[0052] For example, in the example in Fig. 6, as indicated in a candidate character string
field 231-1 of the first decision table 230-1, "ZZZZZ-FM" is the only candidate character
string. That is, in the example in Fig. 6, the ten stored items of the first character
information are all "ZZZZZ-FM". In the example in Fig. 7, candidate character strings
indicated in a candidate character string field 231-2 of the second decision table
230-2 are obtained from the ten items of the first character information 211 stored
in the first character information table 210 shown in Fig. 3. In the example in Fig.
7, three candidate character strings "ZZZZZ-FM", "AAAAAAAA", and "BBBBBBBB" are extracted.
[0053] In the example in Fig. 8, as indicated in a candidate character string field 231-3
of the third decision table 230-3, three candidate character strings "ZZZZZ-FM", "AAAAAAAA",
and "BBBBBBBB" are extracted. In the example in Fig. 9, as indicated in a candidate
character string field 231-4 of the fourth decision table 230-4, three candidate character
strings "ZZZZZ-FM", "YYYYYYYY", and "XXXXXXXX" are extracted. In the example in Fig.
10, as indicated in a candidate character string field 231-5 of the fifth decision
table 230-5, three candidate character strings "ZZZZZ-FM", "AAAAAAAA", and "BBBBBBBB"
are extracted.
[0054] In step 182 in Fig. 5, the broadcast station name identifying unit 144 determines
whether only one candidate character string has been extracted. If it is determined
in step 182 that only one candidate character string has been extracted, the broadcast
station name identifying unit 144 identifies this candidate character string as the
broadcast station name in step 183. The second control method is then completed. If
it is determined in step 182 that plural candidate character strings have been extracted,
the broadcast station name identifying unit 144 proceeds to step 184.
[0055] In the example in Fig. 6, as indicated in the candidate character string field 231-1,
"ZZZZZ-FM" is the only candidate character string, and thus, "ZZZZZ-FM" is identified
as the broadcast station name. The first character information is used for transmitting
a broadcast station name according to the RDS standard. Accordingly, if only one candidate
character string is extracted, it is highly likely that this candidate character string
represents the broadcast station name. In the examples in Figs. 7 through 10, plural
candidate character strings are extracted, and thus, the broadcast station name identifying
unit 144 proceeds to step 184.
[0056] In step 184 in Fig. 5, the broadcast station name identifying unit 144 compares each
candidate character string with the second character information so as to indirectly
compare each item of the first character information with the second character information.
The comparison result in step 184 represents the number of candidate character strings
that are not included in the second character information.
[0057] An include/not-include decision field 232-2 in Fig. 7 indicates whether each of the
candidate character strings indicated in the candidate character string field 231-2
is included in the second character information (Fig. 4). In the example in Fig. 7,
"ZZZZZ-FM" is not included in the second character information 221 (Fig. 4), while
"AAAAAAAA" and "BBBBBBBB" are included in the second character information 221 (Fig.
4). The comparison result is thus "one". An include/not-include decision field 232-3
in Fig. 8 indicates whether each of the candidate character strings indicated in the
candidate character string field 231-3 is included in the second character information.
In the example in Fig. 8, all the candidate character strings are included in the
second character information, and the comparison result is thus "zero".
[0058] An include/not-include decision field 232-4 in Fig. 9 indicates whether each of the
candidate character strings indicated in the candidate character string field 231-4
is included in the second character information. In the example in Fig. 9, none of
the candidate character strings are included in the second character information,
and the comparison result is thus "three". An include/not-include decision field 232-5
in Fig. 10 indicates whether each of the candidate character strings indicated in
the candidate character string field 231-5 is included in the second character information.
In the example in Fig. 10, all the candidate character strings are included in the
second character information, and the comparison result is thus "zero".
[0059] In step 185 in Fig. 5, the broadcast station name identifying unit 144 determines
based on the comparison result obtained in step 184 whether there is only one candidate
character string that is not included in the second character information. If it is
determined in step 185 that there is only one candidate character string that is not
included in the second character information, the broadcast station name identifying
unit 144 identifies this candidate character string as the broadcast station name
in step 186. The second control method is then completed. If it is determined in step
185 that all the candidate character strings are included in the second character
information or that there are two or more candidate character strings that are not
included in the second character information, the broadcast station name identifying
unit 144 proceeds to step 187.
[0060] In the example in Fig. 7, "ZZZZZ-FM" is the only candidate character string that
is not included in the second character information (Fig. 4), and is thus identified
as the broadcast station name. While the first character information is used for transmitting
a broadcast station name according to the RDS standard, the second character information
is used for transmitting various items of information including a broadcast station
name. From the viewpoint of effective use of character information, when information
concerning a broadcast station name is included in the first character information,
the second character information usually includes other items of information. Consequently,
when there is only one candidate character string that is not included in the second
character information (Fig. 4), it is highly likely that this candidate character
string represents the broadcast station name.
[0061] In the examples in Figs. 8 through 10, the comparison result obtained in step 184
is "zero" or "three". The broadcast station name identifying unit 144 thus proceeds
to step 187.
[0062] In step 187 in Fig. 5, the broadcast station name identifying unit 144 counts, as
the appearance frequency, how many times each candidate character string appears among
the plurality of items of the first character information obtained at different times.
[0063] Appearance frequency fields 233-3, 233-4, and 233-5 respectively shown in Figs. 8,
9, and 10 each indicate the appearance frequency of the corresponding candidate character
string. In the example in Fig. 8, the appearance frequency of "ZZZZZ-FM" is "5", the
appearance frequency of "AAAAAAAA" is "3", and the appearance frequency of "BBBBBBBB"
is "2". In the example in Fig. 9, the appearance frequency of "ZZZZZ-FM" is "5", the
appearance frequency of "YYYYYYYY" is "4", and the appearance frequency of "XXXXXXXX"
is "1". In the example in Fig. 10, the appearance frequency of "ZZZZZ-FM" is "4",
the appearance frequency of "AAAAAAAA" is "4", and the appearance frequency of "BBBBBBBB"
is "2".
[0064] In step 188 in Fig. 5, the broadcast station name identifying unit 144 determines
whether, among the candidate character strings extracted in step 181, only one candidate
character string appears most frequently among the plurality of items of the first
character information. If it is determined in step 188 that there is only one candidate
character string that appears most frequently among the candidate character strings
that are not included in the second character information, the broadcast station name
identifying unit 144 proceeds to step 189 and identifies this candidate character
string as the broadcast station name. The second control method is then completed.
In this manner, the broadcast station name identifying unit 144 identifies the broadcast
station name based on the comparison result obtained in step 184 and the appearance
frequency determined in step 187. If it is determined in step 188 that two or more
candidate character strings appear most frequently among the candidate character strings
that are not included in the second character information, the broadcast station name
identifying unit 144 proceeds to step 190.
[0065] In the example in Fig. 8, the most frequently appearing candidate character string
is only "ZZZZZ-FM", and "ZZZZZ-FM" is thus identified as the broadcast station name.
In the example in Fig. 9, too, the most frequently appearing candidate character string
is only "ZZZZZ-FM", and "ZZZZZ-FM" is thus identified as the broadcast station name.
In the example in Fig. 10, there are two most frequently appearing candidate character
strings, that is, "ZZZZZ-FM" and "AAAAAAAA". The broadcast station name identifying
unit 144 thus proceeds to step 190.
[0066] In step 190, the broadcast station name identifying unit 144 compares each of the
candidate character strings with predetermined keywords that are highly likely to
be used for the broadcast station names such as "FM" or "Station". These predetermined
keywords are stored in the storage device 130. The predetermined keywords may be other
character strings.
[0067] A keyword field 234-5 in Fig. 10 indicates whether each of the candidate character
strings in the candidate character string field 231-5 matches at least one of the
predetermined keywords. In Fig. 10, only "ZZZZZ-FM" matches the keyword "FM".
[0068] In step 191, the broadcast station name identifying unit 144 determines whether or
not there is only one candidate character string that includes at least one of the
predetermined keywords among the candidate character strings that appear most frequently.
If it is determined in step 191 that there is only one candidate character string
that includes at least one of the predetermined keywords among the candidate character
strings that appear most frequently, the broadcast station name identifying unit 144
identifies this candidate character string as the broadcast station name in step 192.
The second control method is then completed. In this manner, the broadcast station
name identifying unit 144 identifies the broadcast station name based on a comparison
result of comparing each candidate character string with at least one of predetermined
keywords, that is, based on a comparison result of comparing the first character information
with at least one of predetermined keywords.
[0069] In the example in Fig. 10, "ZZZZZ-FM" is the only candidate character string including
a predetermined keyword, and is thus identified as the broadcast station name.
[0070] If it is determined in step 191 that none of the candidate character strings include
these predetermined keywords or two or more candidate character strings include these
predetermined keywords, the broadcast station name identifying unit 144 does not identify
the broadcast station name in step 193. The second control method is then completed.
(Conclusion)
[0071] According to the embodiment, the need to store all broadcast station names and to
compare the first character information with all the broadcast station names is eliminated.
It is thus possible to speedily identify a broadcast station name with a small storage
capacity.
[0072] According to the embodiment, the broadcast station name identifying unit 144 extracts
one or more candidate character strings which appear at least one time as the first
character information, from among a plurality of items of the first character information
obtained at different times. The broadcast station name identifying unit 144 then
compares each candidate character string with the second character information and
obtains a comparison result. If it is determined based on the comparison result that
there is only one candidate character string that is not included in the second character
information, the broadcast station name identifying unit 144 identifies this candidate
character string as the broadcast station name. It is thus possible to precisely identify
the broadcast station name by excluding candidate character strings included in the
second character information that are unlikely to be the broadcast station name.
[0073] According to the embodiment, as a result of counting, as the appearance frequency,
how many times each candidate character string appears among the plurality of items
of the first character information, the broadcast station name identifying unit 144
identifies the broadcast station name based on the above-described comparison result
and the appearance frequency. It is thus possible to identify the broadcast station
name further precisely, based on the assumption that the first character information
used for transmitting a broadcast station name is highly likely to be the broadcast
station name.
[0074] According to the embodiment, if it is determined that there is not only one candidate
character string that is not included in the second character information, and that
there is only one candidate character string that appears most frequently among the
candidate character strings that are not included in the second character information,
the broadcast station name identifying unit 144 identifies the candidate character
string that appears most frequently as the broadcast station name. It is thus possible
to identify the broadcast station name further precisely, based on the appearance
frequency in addition to the comparison result of comparing the first character information
with the second character information. A case in which it is determined that there
is not only one candidate character string that is not included in the second character
information includes at least one of a case in which two or more candidate character
strings are not included in the second character information and a case in which all
the candidate character strings are included in the second character information.
[0075] According to the embodiment, if it is not determined based on the comparison result
that there is only one candidate character string that is not included in the second
character information and if, among one or more candidate character strings which
appear at least one time as the first character information, two or more candidate
character strings appear most frequently among the plurality of items of the first
character information, the broadcast station name identifying unit 144 identifies,
among the two or more most frequently appearing candidate character strings, a candidate
character string including at least one keyword as the broadcast station name. Preparing
of keywords that are likely to be included in broadcast station names enhances the
precision in identifying the broadcast station name.
[0076] According to the embodiment, the broadcast station name identifying unit 144 identifies
the broadcast station name based on the result of comparing the first character information
with one or more keywords. Preparing of keywords that may be used for identifying
the broadcast station names enhances the precision in identifying the broadcast station
name.
(Modified Examples)
[0077] According to one modified example, the broadcast station name identifying unit 144
starts identifying the broadcast station name upon detecting that a plurality of items
of the first character information obtained at different times are different from
each other.
[0078] According to this modified example, if it is likely that the first character information
has been transmitted according to the dynamic PS system, the broadcast station name
can be identified precisely. If it is likely that the first character information
has been transmitted according to the RDS standard, processing necessary for executing
the second control method may be omitted, thereby reducing the processing load on
the broadcast receiving apparatus 100.
[0079] The present invention is not restricted to the above-described embodiment. That is,
within the technical scope of the invention and equivalents thereof, those skilled
in the art may make various changes to the components described in the embodiment,
make combinations and subcombinations for the components, and may replace at least
some of these components by other components.
[0080] The present invention is applicable to various broadcast receiving apparatuses for
receiving broadcast waves carrying first character information and the second character
information multiplexed with an audio signal. The first character information is used
for transmitting a broadcast station name, and the second character information includes
character information other than the broadcast station name. Such a broadcast receiving
apparatus may be a receiver for FM radio broadcasting only or a receiver for FM radio
broadcasting and AM radio broadcasting. The broadcast receiving apparatus may be an
apparatus installed in a vehicle or may be part of an apparatus including another
function, such as a vehicle navigation function. The broadcast receiving apparatus
may include the function of receiving broadcasts in a different area.
[0081] A broadcast receiving apparatus (100) receives broadcast waves carrying a data signal
and an audio signal multiplexed with each other. The data signal transmits first character
information and second character information. The first character information is used
for transmitting a broadcast station name. The second character information includes
character information other than the broadcast station name. The broadcast receiving
apparatus (100) includes the following elements. A receiver (110) receives the broadcast
waves transmitted from the broadcast station. A data signal obtaining unit (141) obtains
the data signal from the received broadcast waves. A character information obtaining
unit (143) obtains the first character information and the second character information
from the obtained data signal. A broadcast station name identifying unit (144) identifies
the broadcast station name, based on a comparison result of comparing the first character
information with the second character information.
1. A broadcast receiving apparatus (100) for receiving broadcast waves, the broadcast
waves carrying a data signal and an audio signal multiplexed with each other, the
data signal being capable of transmitting first character information and second character
information, the first character information being used for transmitting a broadcast
station name, the second character information including character information other
than the broadcast station name, the broadcast receiving apparatus (100) comprising:
a receiver (110) for receiving the broadcast waves transmitted from the broadcast
station;
a data signal obtaining unit (141) for obtaining the data signal from the received
broadcast waves;
a character information obtaining unit (143) for obtaining the first character information
and the second character information from the obtained data signal; and
a broadcast station name identifying unit (144) for identifying the broadcast station
name, based on a comparison result of comparing the first character information with
the second character information.
2. The broadcast receiving apparatus (100) according to Claim 1, wherein:
the broadcast station name identifying unit (144) extracts one or more candidate character
strings appearing at least one time as the first character information from among
a plurality of items of the first character information obtained at different times;
the broadcast station name identifying unit (144) obtains the comparison result of
comparing the first character information with the second character information indirectly
by comparing the candidate character strings with the second character information;
the broadcast station name identifying unit (144) determines, based on the comparison
result of comparing the first character information with the second character information,
whether or not there is only one candidate character string that is not included in
the second character information; and
if it is determined that there is only one candidate character string that is not
included in the second character information, the broadcast station name identifying
unit (144) identifies the candidate character string that is not included in the second
character information as the broadcast station name.
3. The broadcast receiving apparatus (100) according to Claim 2, wherein:
the broadcast station name identifying unit (144) counts, as appearance frequency,
how many times each of the candidate character strings appears among the plurality
of items of the first character information; and
the broadcast station name identifying unit (144) identifies the broadcast station
name further based on the appearance frequency.
4. The broadcast receiving apparatus (100) according to Claim 3, wherein, if it is determined
that there is not only one candidate character string that is not included in the
second character information, and that there is only one candidate character string
that appears most frequently among the candidate character strings that are not included
in the second character information, the broadcast station name identifying unit (144)
identifies the candidate character string that appears most frequently as the broadcast
station name.
5. The broadcast receiving apparatus (100) according to Claims 4, wherein the broadcast
station name identifying unit (144) identifies the broadcast station name further
based on a comparison result of comparing the first character information with at
least one of predetermined keywords.
6. The broadcast receiving apparatus (100) according to Claim 5, wherein, if it is determined
that there is not only one candidate character string that is not included in the
second character information, that there is not only one candidate character string
that appears most frequently among the candidate character strings that are not included
in the second character information, and that there is only one candidate character
string that includes at least one of the predetermined keywords among the candidate
character strings that appear most frequently, the broadcast station name identifying
unit (144) identifies the candidate character string that includes at least one of
the predetermined keywords as the broadcast station name.
7. The broadcast receiving apparatus (100) according to one of Claims 1 to 6, wherein
the broadcast station name identifying unit (144) starts identifying the broadcast
station name upon detecting that a plurality of items of the first character information
obtained at different times are different from each other.
8. A control method for a broadcast receiving apparatus (100), the broadcast receiving
apparatus (100) receiving broadcast waves, the broadcast waves carrying a data signal
and an audio signal multiplexed with each other, the data signal being capable of
transmitting first character information and second character information, the first
character information being used for transmitting a broadcast station name, the second
character information including character information other than the broadcast station
name, the control method comprising:
a step (171) of receiving the broadcast waves transmitted from the broadcast station;
a step (172) of obtaining the data signal from the received broadcast waves;
a step (173) of obtaining the first character information and the second character
information from the obtained data signal; and
a step (186, 189, 192) of identifying the broadcast station name, based on a comparison
result of comparing the first character information with the second character information.
9. A control program for a broadcast receiving apparatus (100), the control program causing
a computer to execute the control method according to Claim 8.