Technical field
[0001] The present invention relates to, for example, an RDS radio broadcasting receiver.
Background art
[0002] Patent Literature 1 discloses a radio broadcasting receiver that: preferentially
extracts PI code information from all the multiple broadcasting signals in the broadcast
band; preferentially stores this PI code information in a storage means; and then,
extracts information data other than the PI code information; and stores and updates
the information data other than the PI code information in the storage means.
[0003] Patent Literature 2 discloses a radio broadcast receiver that: executes seek operation
(band scanning) in response to a predetermined operation by the user; PI code information
just before the seek operation is stored in a RAM; a timer is prepared; the timer
is started when the PI code of a broadcasting station detected during the seek operation
does not match the PI code stored in the RAM; when a predetermined operation is detected
before a predetermined period of time has lapsed, the PI code of the broadcasting
station detected during the seek operation is additionally stored in the RAM; and
a seek operation is restarted.
[0004] Patent Literature 3 discloses a technology that, upon receiving communication data,
sequentially packets the communication data and transmits the result.
Citation list
Patent Literature
Summary of the Invention
Technical Problem
[0006] However, the methods described in Patent Literatures 1 and 2 have a problem that
it is not possible to reduce the period of time to perform band scanning for all the
frequencies.
[0007] The present invention was accomplished in view of the above-described problems. It
is therefore an object of the present invention to provide a radio broadcasting receiver
that can reduce the period of time required for band scanning.
Solution to the Problem
[0008] A radio broadcasting receiver is provided that receives a radio broadcast wave multiplexed
with an audio signal corresponding to a broadcast program and a broadcast-related
information signal including first information about the broadcast program. The radio
broadcasting receiver includes a control part that performs band scanning to detect
whether or not broadcasting can be received for each frequency.
At a time of the band scanning, the control part performs operation of acquisition
of the first information when both following conditions are satisfied: a condition
that the broadcasting can be received at a selected frequency; and a condition that
the first information corresponding to the selected frequency does not exist in a
previous list of receivable frequencies created at a time of previous band scanning
when the previous list of receivable frequencies is referred.
Brief Description of the Drawings
[0009]
- FIG. 1
- is a block diagram showing the configuration of a radio broadcasting receiver according
to Embodiment 1 of the present invention;
- Figs. 2(a) and 2(b)
- explain band scanning of the radio broadcasting receiver according to Embodiment 1
of the present invention;
- Figs. 3(a) and (b)
- explain arrangement of the period of times for band scanning and the period of times
for data acquisition;
- Figs. 4(a) and (b)
- each explain a list of receivable frequencies;
- FIG. 5
- is a flowchart explaining a process of a control part according to Embodiment 1 of
the present invention; and
- FIG. 6
- is a flowchart explaining a process of the control part according to Embodiment 2
of the present invention.
Description of Embodiments
[0010] FIG. 1 is a block diagram showing the configuration of a radio broadcasting receiver
according to Embodiment 1 of the present invention.
[0011] Now, Embodiment 1 of the present invention will be described in detail with reference
to FIG. 1. The radio broadcasting receiver shown in FIG. 1 is an RDS (radio data system)
radio broadcasting receiver that multiplexes an
FM broadcasting signal with an RDS data signal (hereinafter referred to as "broadcast-related
information signal) in the frequency domain.
The broadcast-related information signal carries various information elements related
to broadcasting with information content data including an audio signal and traffic
information associated with a broadcast program.
These various information elements contained in this broadcast-related information
signal include, for example, the following information elements: PI code information
that allows identification of the program and is unique to a broadcasting station;
TP code information that indicates whether or not the station can support traffic
information; PTY code information that indicates program types (news, sport, music
and so forth); PS name information that indicates data showing the name of a broadcasting
station; and RT data information that is character data transmitted with an audio
signal from the broadcasting station side.
With embodiments of the present invention, PI code information and PS name information
will be used among the above-described various information elements (see FIG. 4).
However, it is by no means limiting, and it is possible to combine and replace information
with any information as long as these various information elements are contained in
a broadcast-related information signal.
[0012] Various convenient methods of using this PI code information have been known. For
example, there is a method of using PI code information as follows. A case is possible
where one program is broadcasted using different frequencies. In addition, another
case is possible where one program is broadcasted from different broadcasting stations.
In this case, the program is broadcasted with different frequencies and also different
PS name information (the names of broadcasting stations).
Here, the user essentially requires to continuously listen to the program which the
user is listening to without any particular operation. In order to support this user's
request, PI code information is used. To be more specific, when the reception condition
of the program which the user is listening to becomes worse (including inability to
hear), an RDS radio broadcasting receiver automatically changes the frequency for
the subsequent reception to another frequency having the same PI code information
as that of the program which the user is listening to.
For such a use, an RDS radio broadcasting receiver needs to always have the latest
PI code information. In addition, PS name information is also required to provide
broadcasting station information to the user. Nonetheless, the urgent need of PS name
information is lower than of PI code information.
Incidentally, although details will be explained later with reference to FIG. 2 and
FIG. 3, it is not preferable to search always PI code information and PS name information
for all the frequencies because of reducing the most important period of time over
which a broadcasting station with the frequency being tuned acquires broadcast content
data, and therefore the reception capability of the broadcasting station deteriorates.
Moreover, there is another problem that by searching always PI code information and
PS name information for all the frequencies, the period of time for acquisition of
data of traffic information contained in a broadcast-related information signal is
reduced. It is therefore another object of the present invention to solve this problem
with embodiments.
[0013] The RDS radio broadcasting receiver obtains an FM broadcasting signal obtained by
receiving a broadcast wave and demodulates an audio signal corresponding to this broadcast.
Moreover, the RDS radio broadcasting receiver detects the broadcast-related information
signal from the FM broadcasting signal to obtain the above-described various information
elements. Then, the RDS radio broadcasting receiver uses this broadcast-related information
signal to realize various functions.
Embodiment 1
[0014] Now, the configuration of the RDS radio broadcasting receiver will be described with
reference to FIG. 1. An antenna 1 supplies to a frontend 2 an FM wave receiving signal
obtained by receiving an FM broadcasting wave with which a broadcast-related information
signal is multiplexed. This FM wave receiving signal is converted to the intermediate
frequency (IF) of 10.7 MHz after the radio wave for a desired broadcasting station
is selected at frontend 2.
Then, the FM wave receiving signal is amplified by an IF amplifier 3. Here, the frontend
2 has a mixer 2a and a PLL circuit 2b. Then, the frontend 2 obtains a local signal
to the mixer 2a by a PLL synthesizer method using the PLL circuit 2b including a programmable
divider (not shown). The frontend 2 sets a receivable frequency according to a command
for a tuning frequency transmitted from a control part 10 described later. In this
case, the frontend 2 performs tuning according to the frequency of this local signal.
[0015] The FM signal of 10.7 MHz is amplified by the IF amplifier 3 to satisfactorily control
the amplitude, output to the FM wave demodulator 4, and demodulated as an audio signal.
A level detector 14 detects the level (field intensity) of a received signal based
on the IF signal level in the IF amplifier 3 and supplies the detected level to the
control part 10.
A local detector 8 outputs a local detection signal when both the following conditions
are satisfied: a condition that the IF signal level in the IF amplifier 3 is equal
to or higher than a predetermined level; and detected output with an S-curve characteristic
in the FM demodulator 4 is within the range of a predetermined level. Here, this local
detection signal indicates that tuning for the broadcast wave from the broadcasting
station has been finished.
Then, this local detection signal is supplied to the control part 10. The control
part 10 performs control of the frontend 2, according to the level of the received
signal supplied from the level detector 14 and the local detection signal supplied
from the local detector 8. In addition, using the local detection signal, the control
part 10 determines whether or not a broadcast signal is sent at the selected frequency
(step ST02 and step ST03 in FIG. 6 described later).
[0016] A stereo demodulating circuit 5 demodulates the audio signal from the FM demodulator
4 to a stereo signal, and supplies the stereo signal to an amplifier. The amplifier
6 appropriately amplifies the audio signal supplied from the stereo demodulating circuit
5, and supplies the result to a speaker 7. The speaker 7 converts the audio signal
amplified by the amplifier 6 into an acoustic oscillation.
[0017] The storage part 11 stores necessary information according to commands from the control
part 10. In particular, with Embodiment 1 of the present invention, the storage part
11 serves to store a latest list of receivable frequencies and provide the latest
list to the control part 10 according to need. Here, the list of receivable frequencies
is referred and updated every band scanning.
With the present embodiment, the list of receivable frequencies before update is referred
to as the previous list of receivable frequencies, which is targeted for reference.
That is, in FIG. 5 described later, the list of receivable frequencies before band
scanning may be the previous list of receivable frequencies.
[0018] The RDS signal detecting circuit 9 detects a broadcast-related information signal
(e.g., PI code information and PS name information) from the detected output from
the FM modulator 4, and supplies the signal to the control part 10. The operating
part 13 generates operation signals according to various operations by the user and
supplies these signals to the control part 10.
The display part 12 displays images or characters based on various display data supplied
from the control part 10. With Embodiment 1 of the present invention, the display
part 12 displays the name of a broadcasting station based on PS name information.
[0019] When the operating part 13 issues a command to fully search for channel selection,
the control part 10 performs full search operation for channel selection. During this
full search operation for channel selection, all the frequencies that can be used
for FM broadcasting, are sequentially searched.
Then, all of the various information elements such as the frequency used for the broadcast
and the broadcast-related information signal corresponding to this frequency are obtained
by the search. The control part 10 generates the latest full list of receivable frequencies,
based on the acquired various information elements.
Then, the generated list of receivable frequencies is stored in the storage part 11.
It is preferred to automatically issue a command for full search for channel selection
by the control part 10. Alternatively, such a command may be issued by pushing for
example, a search key for channel selection provided in the operating part 13, by
the user.
In addition, full search for channel selection may be automatically performed by the
control part 10 every predetermined period of time. The control part 10 may perform
search with a less amount of information slightly than in full search for channel
selection.
The band scanning performed with Embodiment 1 of the present invention is simpler
than the full search for channel selection (the obtained amount of information is
less than in the full search for channel selection), and therefore can be performed
appropriately in a short period of time and at a high frequency. Moreover, band scanning
is usually performed by the control part 10 without the user's operation.
[0020] Here, band scanning with Embodiment 1 of the present invention will be explained
with reference to FIG. 2 and FIG. 3. Figs. 2(a) and 2(b) explain band scanning of
the radio broadcasting receiver according to Embodiment I of the present invention.
Figs. 3(a) and 3(b) explain arrangement of the period of times for band scanning and
the period of times for data acquisition when band scanning is performed with the
method shown in FIG. 2.
To be more specific, FIG. 2(b) and FIG. 3(b) explain a method of band scanning according
to Embodiment 1 of the present invention. FIG. 2(a) and FIG. 3(a) are comparative
examples in a case of full search for channel selection.
[0021] When band scanning is simply performed, full search for channel selection is performed
as shown in FIG. 2(a), and therefore operation of acquisition of PI code information
and PS name information is performed for all the frequencies at which radio broadcasting
can be received. Then, it takes a predetermined period of time to perform operation
of acquisition of PI code information and PS name information.
Here, as shown in FIG. 2(a), it generally takes a longer period of time to acquire
PS name information than a period of time to acquire PI code information. It is because
PS name information has a larger amount of information than PI code information.
Here, in FIG. 2(a), there are bars in which operation of acquisition of PI code information
is performed but operation of acquisition of PS name information is not performed.
It is because PI code information cannot be acquired within a predetermined period
of time, and naturally there is no PS name information.
In addition, when operation of acquisition of PI code information is performed but
operation of acquisition of PS name information is not performed, a case is possible
where there is PS name information but the reception condition is poor, so that acquisition
of the PS name information is not finished within a predetermined period of time.
[0022] For band scanning, a basic operation is performed for each frequency. The basic operation
for each frequency includes: determining whether or not it is possible to receive
radio broadcasting; when it is possible, performing operation of acquisition of PI
code information; when it is possible to acquire PI code information, performing operation
of acquisition of PS name information (the basic operation corresponds to the process
from step ST02 to step ST16 shown in FIG. 5).
This basic operation of band scanning for each frequency is performed from the lowest
frequency at which FM broadcasting can be received. Then, after one basic operation
is finished, the frequency is increased one step and the same basic operation of band
scanning is performed. The basic operation of band scanning is repeatedly performed
until the highest frequency at which FM broadcasting can be received (see FIG. 5).
[0023] With the method of band scanning as shown in FIG. 2(a), it takes a long period of
time for band scanning as shown in FIG. 3(a). Therefore, for example, when band scanning
operations are performed at predetermined time intervals, the proportion of data acquisition
time to the processing time required for one band scanning operation reduces, and
therefore an available amount of information on data transmitted by the broadcasting
station may be reduced.
Here, the data that can be acquired at the time of data acquisition is information
content data such as traffic information. However, it is by no means limiting to information
content data such as traffic information.
Here, with Embodiment 1 of the present invention, it is assumed that band scanning
operations is performed at predetermined time intervals. However, it is by no means
limiting and band scanning operations may not be necessarily performed at predetermined
time intervals.
[0024] With Embodiment 1 of the present invention, a period of time for band scanning is
reduced by keeping and using the previous list of receivable frequencies. To be more
specific, as shown in FIG. 2(b), for band scanning, operation of acquisition is performed
for only PI code information and PS name information corresponding to the reception
frequency which is not in the previous list of receivable frequencies.
That is, at the first band scanning, operation of acquisition of PI code information
(with PS name information) is performed for all frequencies as shown in FIG. 3(a).
Then, after the first band scanning, operation of acquisition of PI code information
(with PS name information) is performed for only a newly-receivable frequency as shown
in FIG. 3(b).
That is, the period of time required for the first band scanning is the same as in
FIG. 3(a), but the period of time required for each band scanning after the first
band scanning is significantly shorter than that. This means that the proportion of
the period of time to acquire the data transmitted from the broadcasting station to
the processing time required for band scanning, increases.
The period of time for band scanning is reduced, so that it is possible to perform
band scanning and data acquisition at a higher frequency (see Figs. 3(a) and 3(b),
comparing the respective frequencies of band scanning). That is, it is possible to
perform band scanning at a high frequency.
[0025] FIG. 4(a) and FIG. 4b) each explain a list of receivable frequencies according to
Embodiment 1 of the present invention.
[0026] As shown in Figs. 4(a) and (b), each list of receivable frequencies includes receivable
frequencies, PI code information corresponding to the receivable frequencies and PS
name information corresponding to the receivable frequencies. However, it is by no
means limiting, and a list may include other various information elements (for example,
TP code information, PTY code information, RT data information, and other information
generated and used by the radio broadcasting receiver).
FIG. 4(a) shows a list of receivable frequencies having already been created before
band scanning (i.e. the previous list of receivable frequencies). FIG. 4 (b) shows
a list of receivable frequencies after band scanning is performed (i.e. the latest
list of receivable frequencies).
Here, the part written as "←new" is newly created by performing band scanning. In
FIG. 4, at frequency f14, a program with PI code information C009 and PS name information
"FM Yokohama", is detected by band scanning. In addition, at frequency f29, a program
with PI code information C025 and PS name information "Saitama FM," is detected by
band scanning.
[0027] FIG. 5 is a flowchart explaining a process of the control part 10 according to Embodiment
1 of the present invention.
[0028] When band scanning is started, the control part 10 starts step ST01 in the process.
In step ST01, in order to perform band scanning, the control part 10 commands to the
frontend 2 to tune the frequency to the lowest frequency among the frequencies at
which FM broadcasting can be received (hereinafter, see FIG. 1 in addition to FIG.
5).
By this means, an FM signal at the tuned frequency (=lowest frequency) is provided
to the IF amplifier 3 and the FM modulator 4. After step ST01 has been executed, the
step in the process of the control part 10 moves to the next step ST02.
[0029] In step ST02, seek operation is performed. To be more specific, the control part
10 detects a local detection signal from the local detector 8. Here, the local detector
8 outputs the local detection signal when both the following conditions are satisfied:
a condition that the IF signal level in the IF amplifier 3 is equal to or higher than
a predetermined level; and a condition that detected output with an S-curve characteristic
in the FM demodulator 4 is within the range of a predetermined level. After step ST02
has been executed, the step in the process of the control part 10 moves to the next
step ST03.
[0030] In step ST30, the control part 10 determines whether or not radio broadcasting can
be received at the set frequency. To be more specific, the control part 10 detects
whether or not a local detection signal is output from the local detector 8, and,
when a local detection signal is output, determines that radio broadcasting can be
received. On the other hand, when a local detection signal is not output, the control
part 10 determines that FM broadcasting cannot be received.
Then, when the control part 10 determines that FM broadcasting can be received, the
step in the process of the control part 10 moves to step ST04. On the other hand,
when the control part 10 determines that FM broadcasting cannot be received, the step
in the process of the control part 10 moves to step ST17.
[0031] In step ST04, the control part 10 writes the set frequency to the latest list of
receivable frequencies, as a receivable frequency. Here, at this step, the PI code
information and the PS name information corresponding to this new frequency has not
been stored yet. After step ST04 has been executed, the step in the process of the
control part 10 moves to the next step ST05.
[0032] In step ST05, the control part 10 determines whether or not the PI code information
corresponding to the frequency set in the latest list of receivable frequencies exists
in the previous list of receivable frequencies. To be more specific, the control part
10 refers to the storage part 11 and determines whether or not the PI code information
corresponding to the frequency set in the latest list of receivable frequencies, is
written in the previous list of receivable frequencies.
Then, when the PI code information is written in the previous list of receivable frequencies,
the step in the process of the control part 10 moves to step ST06. On the other hand,
when the PI code information is not written in the previous list of receivable frequencies,
the step in the process of the control part 10 moves to step ST09.
[0033] In step ST06, the control part 10 determines whether or not the PS name information
corresponding to the frequency set in the latest list of receivable frequencies exists
in the previous list of receivable frequencies. To be more specific, the control part
10 refers to the storage part 11, and determines whether or not the PS name information
corresponding to the frequency set in the latest list of receivable frequencies, is
written in the previous list of receivable frequencies.
Then, when the PS name information is written in the previous list of receivable frequencies,
the step in the process of the control part 10 moves to step ST07. On the other hand,
the PS name information is not written in the previous list of receivable frequencies,
the step in the process of the control part 10 moves to step ST08.
[0034] In step ST07, the control part 10 reads PI code information and PS name information
from the previous list of receivable frequencies, and writes (copies) the PI code
information and the PS name information to the latest list of receivable frequencies.
After step ST07 has been executed, the step in the process of the control part 10
moves to the next step ST17.
[0035] In step ST08, the control part 10 reads PI code information from the previous list
of receivable frequencies and writes (copies) the PI code information to the latest
list of receivable frequencies. After step ST08 has been executed, the step in the
process of the control part 10 moves to the next step ST17. Here, in this case, operation
of acquisition of PS name information is not performed in the present embodiment.
It is intended to avoid consuming the processing time for acquisition of PS name information
because PS name information is not likely to exist. However, another embodiment is
possible where a process flow including acquisition of PS name information is executed.
[0036] Step ST09, the control part 10 starts operation of acquisition of PI code information.
To be more specific, the control part 10 starts operation of acquisition of PI code
information output from the RDS signal detecting circuit 9. After step ST09 has been
executed, the step in the process of the control part 10 moves to the next step ST10.
[0037] In step ST10, the control part 10 determines whether or PI code information has been
acquired. To be more specific, the control part 10 detects whether or not PI code
information is output from the RDS signal detecting circuit 9, and, when PI code information
is output, determines that PI code information has been acquired.
On the other hand, when PI code information has not been output, PI code information
has not been acquired. Then, the control part 10 determines that PI code information
has been acquired, the step in the process of the control part 10 moves to step ST12.
On the other hand, when the control part 10 determines that PI code information has
not been acquired, the step in the process of the control part 10 moves to step ST11.
[0038] In step ST11, the control part 10 determines whether or not the expended period of
time exceeds the period of time permitted for operation of acquisition of PI code
information. To be more specific, the control part 10 compares between the limited
time for operation of acquisition of PI code information set and stored in the storage
part 11 and the elapsed period of time from the start of the operation of acquisition
of PI code information.
Then, when the elapsed period of time from the start of the operation of acquisition
of PI code information is shorter than the limited time for operation of acquisition
of PI code information, the step in the process of the control part 10 moves to step
ST10 to continue the operation of acquisition of PI code information.
On the other hand, when the elapsed period of time from the start of the operation
of acquisition of PI code information is longer than the limited time for operation
of acquisition of PI code information, the operation of acquisition of PI code information
is stopped and the step in the process of the control part 10 moves to step ST17.
Here, the limited time for operation of acquisition of PI code information is, in
other words, the time to stop operation of acquisition of PI code information.
[0039] In step ST12, the control part 10 writes PI code information in association with
the frequency set in the latest list of receivable frequencies. To be more specific,
the control part 10 writes PI information in association with the frequency set in
the latest list of receivable frequencies in the storage part 11. Here, in this step,
PS name information corresponding to this new frequency has not been stored. After
step ST12 has been executed, the step in the process of the control part 10 moves
to the next step ST13.
[0040] In step ST13, the control part 10 performs operation of acquisition of PS name information.
To be more specific, the control part 10 performs operation of acquisition of PS name
information output from the RDS signal detecting circuit 9. After step ST13 has been
executed, the step in the process of the control part 10 moves to the next step ST14.
[0041] In step ST14, the control part 10 determines whether or not PS name information has
been acquired. To be more specific, the control part 10 detects whether or not PS
name information has been output from the RDS signal detecting circuit 9, and, when
PS name information has been output, determines that PS name information has been
acquired.
On the other hand, when PS name information has not been output, the control part
10 determines that PS information has not been acquired. Then, when the control part
10 determines that the PS name information has been acquired, the step in the process
of the control part 10 moves to step ST16. On the other hand, when the control part
10 determines that PS name information has not been acquired, the step in the process
of the control part 10 moves to step ST15.
[0042] In step ST15, the control part 10 determines whether or not the expended period of
time exceeds the period of time permitted for operation of acquisition of PS name
information. To be more specific, the control part 10 compares between the limited
time for operation of acquisition of PS name information set and stored in the storage
part 11 and the elapsed period of time from the start of the operation of acquisition
of PS name information.
Then, when the elapsed period of time from the start of the operation of acquisition
of PS name information is shorter than the limited time for operation of acquisition
of PS name information, the step in the process of the control part 10 moves to step
ST14 to continue the operation of acquisition of PS name information.
On the other hand, when the elapsed period of time from the start of the operation
of acquisition of PS name information is longer than the limited time for operation
of acquisition of PS name information, the operation of acquisition of PS name information
is stopped and the step in the process of the control part 10 moves to step ST17.
Here, the limited time for operation of acquisition of PS name information is, in
other words, the time to stop operation of acquisition of PS name information.
Here, it is preferred that the period of time from the beginning to the end of an
operation of acquisition of PI code information (shown in step ST11) is set shorter
than the period of time from the beginning to the end of an operation of acquisition
of PS name information (shown in step ST15).
It is because PI code information is smaller than PS name information in quantity,
and therefore can be acquired for a shorter period of time. This allows completion
of band scanning for a short period of time.
[0043] In step ST16, the control part 10 writes PS name information in association with
the frequency set in the latest list of receivable frequencies. To be more specific,
the control part 10 writes the PS name information in association with the frequency
set in the latest list of receivable frequencies in the storage part 11. After step
ST16 has been executed, the step in the process of the control part 10 moves to step
ST17.
[0044] Here, the steps from step ST02 to step ST16 in the process correspond to the basic
operation for each frequency. That is, the steps for the basic operation are sequentially
executed for each frequency, so that the band scanning is finished for all the frequencies.
[0045] In step ST17, the set frequency is increased one step. After step ST17 has been executed,
the step in the process of the control part 10 moves to the next step ST18.
[0046] In step ST18, the control part 10 determines whether or not the frequency set in
step ST17 exceeds the highest frequency (upper limit). Then, when the frequency does
not exceed the highest frequency, the control part 10 moves the step in the process
to step ST02 to perform the basic operation for the frequency having been increased
one step in step ST17.
On the other hand, when the frequency exceeds the highest frequency, the process of
the control part 10 ends.
[0047] With Embodiment 1 of the present invention having the above-described configuration,
it is possible to skip the steps to acquire PI code information enclosed in the dashed
line shown in FIG. 5 when the steps do not need to be executed, and therefore finish
band scanning for a short period of time.
This allows execution of band scanning at a high frequency. That is, the proportion
of the period of time for data acquisition to the processing time required for band
scanning is increased, and therefore it is possible to acquire increased amount of
data on FM broadcasting.
As a result, it is possible to increase an amount of received data such as traffic
information on FM broadcasting. In addition, since it is possible to perform band
scanning at a high frequency, the control part 10 can change the frequency at a high
speed, referring to PI code information according to need, in order to allow the user
to continue to listen to the program which the user being listening to.
Moreover, the period of time from the beginning to the end of an operation of acquisition
of PI code information is set shorter than the period of time from the beginning to
the end of an operation of acquisition of PS name information, and therefore it is
possible to finish band scanning for a short period of time.
Furthermore, with the above-described configuration, it is possible to perform band
scanning at a high frequency and for a short period of time without sacrifice which
is decrease in the proportion of the period of time for data acquisition to the processing
time required for band scanning.
Then, since it is possible to perform band scanning at a high frequency and for a
short period of time, even if the reception condition rapidly changes at such as the
exit of a long tunnel, it is possible to provide a significant effect that the latest
list of receivable frequencies can be updated for a short period of time.
Embodiment 2
[0048] FIG. 6 is a flowchart explaining a process of the control part 10 according to Embodiment
2 of the invention. Basically, the configuration, operation and effect shown in FIG.
6 are the same in FIG. 5 except that step ST19 and step ST20 are added to the process.
Therefore, description of the same parts as in FIG. 5 will be omitted.
[0049] In step ST19, the control part 10 determines whether or not there is PS name information
corresponding to the PI code written in the latest list of receivable frequencies.
To be more specific, the control part 10 refers to the storage part 11 and determines
whether or not PS name information corresponding to the PI code written in the latest
list of receivable frequencies, exists.
When the PS name information exists in the storage part 11, the step in the process
of the control part 10 moves to step ST20. On the other hand, when the PS name information
does not exist in the storage part 11, the step in the process of the control part
10 moves to step ST13.
[0050] In step ST20, the control part 10 reads the PS name information from the previous
list of receivable frequencies, and writes the PS name information to the latest list
of receivable frequencies. After step ST20 has been performed, the step in the process
of the control part 10 moves to the next step ST17.
[0051] With Embodiment 2 of the present invention having the above-described configuration,
it is possible to finish band scanning for a shorter period of time than in Embodiment
1 of the present invention. This allows band scanning at a high frequency.
It is because even if PI code information is not acquired and the steps enclosed in
the dashed line shown in FIG.6 are performed, it is possible to skip operation of
acquisition of PS name information, which needs to a longer period of time than the
period of time to acquire PI code information.
[0052] With the above-described embodiments, the radio broadcasting receiver according to
the present invention receives a radio broadcast wave multiplexed with information
content data including an audio signal and traffic information associated with a broadcast
program and a broadcast-related information signal including PI code information associated
with the broadcast program.
Then, the radio broadcasting receiver according to the present invention has the control
part 10 that performs band scanning for detecting whether or not it is possible to
receive broadcasting for each frequency.
In addition, the control part 10 performs operation of acquisition of PI code information
only when both the following conditions are satisfied: a condition that it is possible
to receive broadcasting at the frequency selected at the time of band scanning; and
a condition that when the previous list of receivable frequencies created at the time
of the previous band scanning is referred, there is no PI code information corresponding
to the selected frequency in the previous list of receivable frequencies.
With this configuration, it is possible to finish band scanning for a short period
of time. By this means, it is possible to perform band scanning at a high frequency.
That is, the proportion of the period of time for data acquisition to the processing
time required for band scanning increases, so that it is possible to acquire an increased
amount of information content data including traffic information on FM broadcasting.
As a result, it is possible to improve the sound quality of FM broadcasting and a
success rate of acquiring information such as traffic information.
In addition, since it is possible to perform band scanning at a high frequency, the
control part 10 can change the frequency at a high speed, referring PI code information
according to need, in order to allow the user to continue to listen to the program
which the user being listening to.
[0053] Here, the control part 10 according to the above-described embodiments is an example
of control means. That is, the control means is not necessarily a single means as
long as it provides control in one way or another. For example, distributed control
may be provided by a plurality of control means. Either analog processing or digital
processing is possible. In addition, the storage part 11 is an example of storage
means.
That is, the storage means is not necessarily a single means as long as it provides
storage in one way or another. Storage includes distributed storage. Moreover, either
analog processing or digital processing is possible. The radio broadcasting receiver
according to the present invention is not limited as long as it can receive radio
broadcasting supporting a system for providing broadcast-related information such
as an RDS.
For example, the radio broadcasting receiver according to the present invention may
be an electronic device incorporated in a personal computer, a portable music player,
a mobile phone, a television in a navigation apparatus (car navigation system) and
a transportation device such as a car.
[0054] Step ST03 in the process according to the embodiments of the present invention is
an example of a receivable frequency determination means for determining whether or
not broadcasting can be received according to the present invention. Step ST05 in
the process according to the embodiments of the present invention is an example of
a first information reference and determination means for referring to and determining
first information according to the present invention. Step ST19 in the process of
Embodiment 2 of the present invention is an example of a second information reference
and determination means for referring to and determining first information according
to the present invention.
[0055] PI code information is an example of "first information" of the present invention.
That is, the first information may be TP code information, PTY code information, RT
data information and so forth. In addition, PS name information is an example of "broadcast-related
information other than the first information" of the present invention. That is, broadcast-related
information other than the first information may be TP code information, PTY code
information, RT data information and so forth.
In brief, the present invention can apply any information as long as the order of
the information to be acquired is determined like PI code information and PS name
information, and the rule is established between two information elements such that
the information acquired earlier inevitably determines the information to be acquired
next.
[0056] Although with the present invention, the embodiments have been shown where band scanning
is combined with acquisition of broadcast-related information as a tuner function,
band scanning may be combined with another tuner function such as phase diversity.
This tuner function reduces the period of time for band scanning, and therefore produce
an effect to increase the proportion of period of time over which the tuner function
can serve as a phase diversity tuner to the processing time required for band scanning
in order to improve reception capability.
That is, the present invention applicable to any tuner function that can be combined
with band scanning as long as the function does not need to constantly operate even
when used by the user. It is because a certain period of time can be used for band
scanning.
[0057] In addition, the radio broadcasting receiver according to the present invention does
not necessarily receive an RDS signal in synchronization with an audio signal. That
is, the radio broadcasting receiver according to the present invention is not limited
as long as one can receive an RDS signal. In other words, the present invention is
not limited as long as a radio broadcasting is provided to increase the speed and
the frequency of band scanning.
List of Reference Signs
[0058]
- 1
- = antenna
- 2
- = frontend
- 2a
- = mixer
- 2b
- = PLL circuit
- 3
- = IF amplifier
- 4
- = FM demodulator
- 5
- = stereo demodulating circuit
- 6
- = amplifier
- 7
- = speaker
- 8
- = local detector
- 9
- = RDS signal detecting circuit
- 10
- = control part
- 11
- = storage part
- 12
- = display part
- 13
- = operating part
- 14
- = level detector