JP2005064585A - Receiving apparatus and receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To search receivable channels at a high speed. <P>SOLUTION: While a digital television receiver 20 receives digital broadcast, an analog television receiver 40 repeats the scanning of analog broadcast channels and stores the scanned channels in a channel table. In searching or scanning the digital broadcast channels, the receiver 20 executes the skip scanning or skip searching of channels excluding the analog broadcast channels, thereby shortening a time for searching the digital broadcast channels. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a receiving apparatus including an analog tuner that receives an analog broadcast and a digital tuner that receives a digital broadcast, and a reception method thereof, and more particularly, a reception capable of searching a receivable channel at a high speed in an in-vehicle receiving apparatus. The present invention relates to an apparatus and a receiving method.
[0002]
[Prior art]
In recent years, digital television broadcasting for digitizing and broadcasting video programs has been put into practical use. Digital broadcasting has the advantage that it can realize high image quality, multi-channels, and bidirectionality. In addition to satellite digital broadcasting, digital terrestrial broadcasting has been transferred to digital broadcasting. Use is spreading.
[0003]
In view of this, a receiving apparatus having both a digital tuner for receiving a digital broadcast and an analog tuner for receiving an analog broadcast has been devised. As described above, when both analog broadcasting and digital broadcasting are received, it is necessary to search for a channel on which analog broadcasting is performed and a channel on which digital broadcasting is performed.
[0004]
For example, the broadcast receiving apparatus disclosed in Patent Document 1 performs channel tuning in a broadcasting apparatus capable of receiving both analog broadcast and digital broadcast by executing analog broadcast tuning and digital broadcast channel tuning in parallel. It takes less time to complete.
[0005]
In the receiving apparatus disclosed in Patent Document 2, when the digital tuner receives a digital broadcast, the analog tuner monitors the change in the reception intensity. When the reception intensity of the digital tuner decreases, the reception intensity increases. Are presumed to be broadcasts with the same content.
[0006]
[Patent Document 1]
JP 2001-24537 A
[Patent Document 2]
JP 2001-36424 A
[0007]
[Problems to be solved by the invention]
By the way, in digital broadcasting, when the reception channel is switched, a time of about 1 second is required until screen display and audio output. Especially when switching destination channel frequency is not specified and a receivable channel is searched for and displayed (searched), or all broadcasted channels are searched for (scanned) from a predetermined frequency band This time is a big burden.
[0008]
In Patent Document 1 described above, analog broadcast channel tuning that scans analog broadcast channels and stores receivable channels and digital broadcast channel tuning that scans digital broadcast channels and stores receivable channels are performed in parallel. However, the time required for scanning the digital broadcast channel itself could not be shortened.
[0009]
Furthermore, in a receiving device mounted on a mobile body such as a car, the receivable channel changes according to the change of the location of the mobile body, so that a search or scan is required frequently, and this problem is particularly remarkable.
[0010]
In Patent Document 2 described above, in consideration of the fact that the channel is changed as it moves, the channel on which the same content as the channel whose reception intensity has decreased is estimated, but the viewing broadcast itself is changed. However, it is necessary to perform a conventional search and scan, and the time until receiving a desired broadcast cannot be shortened.
[0011]
That is, the conventional receiving apparatus has a problem that it takes a long time to search and scan a digital broadcast channel, and it has been an important issue to search for a receivable channel at a high speed.
[0012]
The present invention has been made to solve the above-described problems caused by the prior art and to solve the problems. An object of the present invention is to provide a receiving apparatus and a receiving method capable of searching for a receivable channel at a high speed.
[0013]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the object, a receiving apparatus according to claim 1 is a receiving apparatus including an analog tuner that receives an analog broadcast and a digital tuner that receives a digital broadcast, Analog broadcast search means for searching for an analog broadcast channel on which analog broadcast is being performed from a predetermined frequency band, and digitally selectively from channels not used for analog broadcast based on the search result of the analog broadcast search means And a digital broadcast search means for searching for a digital broadcast channel on which broadcast is being performed.
[0014]
According to the first aspect of the present invention, the receiving device searches for channels on which analog broadcasting is performed from the frequency band, and selectively searches for digital broadcasting channels from channels on which analog broadcasting is not performed.
[0015]
According to a second aspect of the present invention, there is provided the receiving apparatus according to the first aspect, wherein the analog broadcast search means uses the analog tuner while the digital tuner is receiving a digital broadcast. It is characterized by searching for broadcast channels.
[0016]
According to the second aspect of the present invention, the receiving apparatus searches for an analog broadcast channel using the analog tuner while the digital tuner is receiving the digital broadcast, and when the analog broadcast is searched for the analog broadcast, Search from channels that are not being used.
[0017]
According to a third aspect of the present invention, in the receiver according to the second aspect, the analog broadcast search means continuously searches for the analog broadcast channel while the digital tuner is receiving the digital broadcast. It is characterized by repetition.
[0018]
According to the third aspect of the present invention, when the digital tuner receives a digital broadcast, the receiving device continuously repeats the search for the analog broadcast channel using the analog tuner to search for the digital broadcast channel. Search from a channel that is not broadcasting analog.
[0019]
According to a fourth aspect of the present invention, in the first to third aspects of the invention, the analog broadcast search means determines whether or not analog broadcast is being performed based on an average value of received radio wave intensity. It is characterized by performing.
[0020]
According to the fourth aspect of the present invention, the receiving device searches for an analog broadcast channel based on the average value of the received radio wave intensity, and selectively searches for a digital broadcast channel from channels where analog broadcasting is not performed.
[0021]
Further, in the receiving device according to the invention of claim 5, in the invention of claims 1 to 4, the analog broadcast search means determines whether or not analog broadcasting is being performed based on a change amount of the received radio wave intensity. It is characterized by performing.
[0022]
According to the fifth aspect of the present invention, the receiving device searches for an analog broadcast channel based on the amount of change in the received radio wave intensity, and selectively searches for a digital broadcast channel from the channels where analog broadcasting is not performed.
[0023]
Further, in the invention according to claim 6, in the invention according to claims 1 to 5, the analog broadcast search means determines whether analog broadcast is being performed based on the stability of the synchronization signal. It is characterized by that.
[0024]
According to the sixth aspect of the present invention, the receiving device searches for an analog broadcast channel based on the stability of the synchronization signal, and selectively searches for a digital broadcast channel from channels on which analog broadcasting is not performed.
[0025]
According to a seventh aspect of the present invention, in the first to sixth aspects of the invention, the analog broadcast search means determines whether the analog broadcast is being performed based on the stability of the color subcarrier. It is characterized by performing.
[0026]
According to the seventh aspect of the present invention, the receiving device searches for an analog broadcast channel based on the stability of the color subcarrier, and selectively searches for a digital broadcast channel from channels that are not subjected to analog broadcast.
[0027]
According to an eighth aspect of the present invention, there is provided a receiving apparatus according to the first to seventh aspects of the present invention, wherein the analog tuner or the digital tuner is receiving a broadcast when the analog tuner or the digital tuner is receiving a broadcast. And a non-broadcast channel search means for detecting a non-broadcast channel in which neither of the digital broadcasts is broadcast, wherein the non-broadcast channel is excluded when the tuner receiving the broadcast scans or searches. To do.
[0028]
According to the eighth aspect of the present invention, when the analog tuner or the digital tuner is receiving the broadcast, the receiving device does not broadcast either the analog broadcast or the digital broadcast using the tuner that does not receive the broadcast. A broadcast channel is detected, and a non-broadcast channel is excluded when a tuner receiving a broadcast scans or searches.
[0029]
A receiving device according to a ninth aspect of the present invention is the receiving device according to any of the first to eighth aspects, wherein a channel to be received by the digital tuner is designated and digital broadcasting is not performed on the designated channel. The digital tuner receives a digital broadcast channel in the vicinity of a designated channel.
[0030]
According to the ninth aspect of the present invention, the receiving device receives a digital broadcast channel in the vicinity of the designated channel when the channel to be received by the digital tuner is designated and the digital broadcast is not performed on the designated channel. To do.
[0031]
According to a tenth aspect of the present invention, there is provided a receiving method using an analog tuner for receiving an analog broadcast and a digital tuner for receiving a digital broadcast, wherein the analog broadcast is performed from a predetermined frequency band. Based on the analog broadcast search process for searching for an analog broadcast channel and the search result of the analog broadcast search process, a digital broadcast channel on which digital broadcast is selectively performed is searched from channels not used for analog broadcast. And a digital broadcast search process.
[0032]
According to the tenth aspect of the invention, in the receiving method, a channel on which analog broadcasting is performed is searched from a frequency band, and a digital broadcasting channel is selectively searched from channels on which analog broadcasting is not performed.
[0033]
According to an eleventh aspect of the present invention, there is provided a receiving method according to the tenth aspect, wherein the analog broadcast search step uses the analog tuner while the digital tuner is receiving a digital broadcast. It is characterized by searching for broadcast channels.
[0034]
According to the eleventh aspect of the present invention, in the receiving method, when the digital tuner receives a digital broadcast, the analog tuner is used to search for an analog broadcast channel, and the analog broadcast is searched when the digital broadcast channel is searched. Search from channels that are not being used.
[0035]
According to a twelfth aspect of the present invention, in the reception method according to the twelfth aspect of the present invention, the analog broadcast search step continuously searches for the analog broadcast channel while the digital tuner is receiving a digital broadcast. It is characterized by repetition.
[0036]
According to the twelfth aspect of the present invention, in the receiving method, when the digital tuner receives the digital broadcast, the search of the analog broadcast channel using the analog tuner is continuously repeated to search for the digital broadcast channel. Search from a channel that is not broadcasting analog.
[0037]
Further, in the reception method according to the invention of claim 13, in the invention of claims 10 to 12, the analog broadcast search step determines whether or not analog broadcast is being performed based on an average value of received radio wave intensity. It is characterized by performing.
[0038]
According to the invention of claim 13, in the receiving method, an analog broadcast channel is searched based on an average value of received radio wave intensity, and a digital broadcast channel is selectively searched from a channel on which no analog broadcast is performed.
[0039]
According to a fourteenth aspect of the present invention, in the reception method according to the tenth to thirteenth aspects of the present invention, the analog broadcast search step determines whether or not the analog broadcast is being performed based on the amount of change in the received radio wave intensity. It is characterized by performing.
[0040]
According to the fourteenth aspect of the present invention, in the receiving method, an analog broadcast channel is searched based on the amount of change in the received radio wave intensity, and a digital broadcast channel is selectively searched from a channel where analog broadcasting is not performed.
[0041]
In the receiving method according to the invention of claim 15, in the invention of claims 10 to 14, the analog broadcast search step determines whether or not analog broadcast is being performed based on the stability of the synchronization signal. It is characterized by that.
[0042]
According to the fifteenth aspect of the present invention, in the receiving method, the analog broadcast channel is searched based on the stability of the synchronization signal, and the digital broadcast channel is selectively searched from the channels where the analog broadcast is not performed.
[0043]
Further, in the reception method according to the invention of claim 16, in the invention of claims 10 to 15, the analog broadcast search step determines whether or not analog broadcast is performed based on the stability of the color subcarrier. It is characterized by performing.
[0044]
According to the sixteenth aspect of the present invention, in the receiving method, an analog broadcast channel is searched based on the stability of the color subcarrier, and a digital broadcast channel is selectively searched from a channel on which no analog broadcast is performed.
[0045]
According to a seventeenth aspect of the present invention, there is provided a receiving method according to the tenth to sixteenth aspects of the present invention, wherein the analog tuner or the digital tuner is receiving a broadcast when the analog tuner or the digital tuner is receiving a broadcast. And a non-broadcast channel search step for detecting a non-broadcast channel in which neither of the digital broadcasts is broadcast, wherein the non-broadcast channel is excluded when the tuner receiving the broadcast scans or searches. To do.
[0046]
According to the seventeenth aspect of the present invention, when the analog tuner or the digital tuner is receiving a broadcast, neither the analog broadcast nor the digital broadcast is broadcast using the tuner that does not receive the broadcast. A broadcast channel is detected, and a non-broadcast channel is excluded when a tuner receiving a broadcast scans or searches.
[0047]
The receiving method according to the invention of claim 18 is the receiving method according to claims 10 to 17, wherein the channel to be received by the digital tuner is designated and digital broadcasting is not performed on the designated channel. The digital tuner receives a digital broadcast channel in the vicinity of a designated channel.
[0048]
According to the eighteenth aspect of the present invention, when the channel to be received by the digital tuner is designated and the digital broadcast is not performed on the designated channel, the reception method receives a digital broadcast channel near the designated channel. To do.
[0049]
DETAILED DESCRIPTION OF THE INVENTION
An in-vehicle television device that is a preferred embodiment of a receiving device and a receiving method according to the present invention will be described below with reference to the accompanying drawings.
[0050]
(Embodiment 1)
First, a schematic configuration of the in-vehicle television device 1 according to the first embodiment will be described. FIG. 1 is a schematic configuration diagram illustrating a schematic configuration of the in-vehicle television device according to the first embodiment. In FIG. 1, the in-vehicle television apparatus 1 includes antennas 2 and 4, a digital television receiver 20, an analog television receiver 40, a main control unit 11, a switching unit 12, and a monitor 13.
[0051]
The digital television receiver 20 is connected to the antenna 2, receives a digital broadcast, and outputs it to the switching unit 12. The analog television receiver 40 is connected to the antenna 4 to receive an analog broadcast and output it to the switching unit 12.
[0052]
The main control unit 11 is a control unit that controls the vehicle-mounted television apparatus 1 as a whole, controls the digital television receiver 20 and the analog television receiver 40, and controls the switching unit 12 to either digital broadcasting or analog broadcasting. Is displayed on the monitor 13.
[0053]
The digital television receiver 20 includes a digital tuner 21, a CPU 22, a channel table 23, an MPEG decoder 24, and a digital demodulator 25 therein.
[0054]
The digital tuner 21 receives a channel specified by the CPU 22. The digital demodulator 25 extracts a TS (Transport Stream) packet from the channel received by the digital tuner 21. The MPEG decoder 24 converts the TS packet into moving image data and outputs it to the switching unit 12.
[0055]
More specifically, the digital demodulation unit 25 includes an AGC (automatic gain control) 31, an ADC (Analog-to-Digital Converter) 32, a data symbol reading unit 33, a decoding processing unit 34, and a TS buffer 35. The ADC 32 converts the received radio wave received by the digital tuner 21 into a digital signal and outputs the digital signal to the data symbol reading unit 33. The data symbol reading unit 33 reads data symbols from the received radio wave digitized by the ADC and outputs the data symbols to the decoding processing unit 34. The AGC 31 is connected to the data symbol reading unit 33 and performs gain control of the digital tuner 21 based on the intensity (reception intensity) of the received radio wave.
[0056]
The decoding processing unit 34 performs decoding processing on the data symbols and takes out TS packets. The TS packets are accumulated in the TS buffer 35 and then output to the decoder 24 by MPEG.
[0057]
The CPU 22 functions as a digital tuner 21, a digital demodulator 25, and a controller that controls the coder 24 using MPEG. Further, the CPU 22 is connected to a channel table 23 composed of a memory such as a RAM. The channel table 23 stores channels on which digital broadcasting is performed, that is, digital broadcasting channels.
[0058]
When the CPU 22 searches for or scans a digital broadcast channel, the CPU 22 stores the result in the channel table 23. Here, the search of the digital broadcast channel is a channel that can be received by searching for a channel that can be received from the current frequency (channel) toward the high frequency side or the low frequency side, that is, a channel used for digital broadcasting. Is a process of receiving and displaying the digital broadcast.
[0059]
The digital broadcast channel scan refers to a process of sequentially determining whether or not reception is possible for all channels in the frequency band and detecting a channel on which digital broadcast is being performed. By performing this scan, the channel table 23 can be completed. Therefore, when changing the channel to be received next, it is possible to receive a broadcast by designating a desired channel without performing a search.
[0060]
The analog television receiver 40 includes an analog tuner 41, a CPU 42, a channel table 43, an IF detector 44, an amplifier 45, an averaging processing unit 46, an AGC 47, and an analog demodulation unit 48.
[0061]
The analog tuner 41 receives a channel specified by the CPU 42. The IF detector 44 performs IF detection on the received radio wave received by the analog tuner 41 and outputs it to the amplifier 45. The amplifier 45 amplifies the output of the IF detector 44 and outputs it to the AGC 47 and the analog demodulator 48 as a composite video signal. The AGC 47 performs gain control of the analog tuner 41 and the amplifier 45 based on the output of the amplifier 45. Further, the averaging processing unit 46 acquires the voltage value of the composite video signal output from the AGC 47, averages several lines, and outputs the average to the CPU.
[0062]
The analog demodulation unit 48 extracts the image signal and the synchronization signal from the composite video signal and outputs them to the switching unit 12. More specifically, the analog demodulator 48 includes a sync separator 51, an AFC 52, a YC separator 53, and an RGB demodulator 54 therein.
[0063]
The sync separator 51 separates the sync signal from the composite video signal and outputs it to the AFC 52. The AFC 52 performs automatic frequency control on the synchronization signal to stabilize it, and supplies it to the RGB demodulation unit 54 and the switching unit 12.
[0064]
On the other hand, the YC separation unit 53 separates the Y signal (luminance signal) and the C signal (color signal) from the composite video signal, and supplies them to the RGB demodulation unit 54. The RGB demodulator 54 performs RGB demodulation on the Y signal and C signal based on the synchronization signal supplied from the AFC 52, and outputs the result to the switching unit 12 as an image signal.
[0065]
The CPU 42 functions as a control unit that controls the analog tuner 41 and the analog demodulation unit 48. Further, the CPU 42 is connected to a channel table 43 constituted by a memory such as a RAM. The channel table 43 stores channels on which analog broadcasting is performed, that is, analog broadcasting channels.
[0066]
The CPU 42 stores the result in the channel table 43 when the analog broadcast channel is searched or scanned. Here, the analog broadcast channel search is a channel that can be received by searching for a channel that can be received from the current frequency (channel) toward the high frequency side or the low frequency side, that is, a channel that is used for analog broadcasting. Is a process for receiving and displaying the analog broadcast.
[0067]
The analog broadcast channel scan refers to a process of sequentially determining whether or not reception is possible for all channels in the frequency band and detecting a channel on which analog broadcast is being performed. By performing this scan, the channel table 43 can be completed. Therefore, when the channel to be received next is changed, the broadcast can be received by designating a desired channel without performing a search.
[0068]
Here, when determining whether or not a broadcast can be received on a certain channel, the CPU 42 determines that the broadcast can be received if the average value output by the averaging processing unit 46 is equal to or greater than a predetermined threshold.
[0069]
Next, specific examples of the channel tables 23 and 43 will be described. The channel table 23 stores digital broadcast channels, and the channel table 43 stores analog broadcast channels. Since the configuration is the same, the channel table 23 will be described here.
[0070]
FIG. 2 is an explanatory diagram for explaining a specific example of the channel table 23. In FIG. 2, the channel table 23a stores presence / absence of broadcast (here, digital broadcast) for a channel assigned to a predetermined frequency band. Specifically, in the channel table 23a, it is stored that broadcasting is performed on 2 channels, 4 channels, and 6 channels.
[0071]
Furthermore, the channel table 23a stores “4 channels” as the channel that the user last viewed. In this way, the last viewing channel by the user is stored because the user originally viewed when the user stopped viewing the digital broadcast, viewed the analog broadcast, and viewed the digital broadcast again. This is because the channel is automatically displayed.
[0072]
By the way, on which channel broadcasting exists depends on the region.
In a television apparatus used in a specific area, once it is necessary to create a channel table, it is not necessary to update the channel table. However, in an in-vehicle television apparatus, the arrangement of channels on which broadcasting is performed varies with the movement.
[0073]
The channel table 23b shown in FIG. 2 is a channel table in which the arrangement of broadcast channels is changed. In the channel table 23a, broadcasting is performed on 2 channels, 4 channels, and 6 channels. On the channel table 23b, broadcasting is performed on 1 channel, 3 channels, 5 channels, and 7 channels.
[0074]
Therefore, in the in-vehicle television device 1, it is necessary to frequently update the channel table as the channel arrangement changes. Further, even if an attempt is made to return to the final viewing channel after the channel arrangement has changed, there is a case where broadcasting is not performed on the channel that was originally viewed.
[0075]
For example, in the channel table 23b, there is no broadcast on channel 6 which is the final viewing channel stored at the time of the channel table 23a. In this case, it is only necessary to perform a search from the last viewing channel to the high frequency side or the low frequency side and receive the first broadcast channel found. In the channel table 23b, the search is started from the 4th channel which is the final viewing channel, and the 3rd channel or the 5th channel in which the broadcast exists is received.
[0076]
On the other hand, when updating the channel table, it is necessary to scan a predetermined frequency band again. However, since the broadcast channel scan confirms the reception of each channel, it takes a long time to complete the update. In particular, in digital broadcasting, it takes about 1 second to confirm the reception of each channel, so that the time until the update is completed is further increased.
[0077]
Here, since the digital broadcast and the analog broadcast cannot use the same channel, each channel is one of no broadcast (no broadcast channel), a digital broadcast channel, and an analog broadcast channel. Therefore, in the in-car television set 1, when scanning a digital broadcast channel, the channel table 43 storing the analog broadcast channel is referred to and the analog broadcast channel is excluded from the frequency band.
[0078]
FIG. 3 is an explanatory diagram for explaining digital broadcast scanning in the in-vehicle television device 1. As shown in the figure, in a normal scan, it is first determined whether or not one channel is a digital broadcast channel, and then it is determined whether or not two channels are digital broadcast channels. After that, the reception confirmation is sequentially executed for 3 channels, 4 channels, 5 channels, 6 channels, and 7 channels.
[0079]
On the other hand, in the scan excluding the analog broadcast channel (skip scan), by referring to the analog broadcast channel table 43, it can be seen that the 2nd, 4th, and 6th channels are analog broadcast channels. After determining whether or not it is a broadcast channel, the reception confirmation for the three channels is executed without performing the reception confirmation for the two channels. Similarly, reception confirmation for channels 4 and 6 is skipped. That is, in skip scan, reception confirmation is executed for 1 channel, 3 channels, 5 channels, and 7 channels.
[0080]
Thus, by skipping the analog broadcast channel, the time required for scanning the digital broadcast channel can be greatly reduced.
[0081]
Further, while the digital television receiver 20 is receiving a digital broadcast, the analog television receiver 40 repeatedly scans the analog broadcast channel and constantly updates the channel table 43, so that the scan by the digital television receiver 20 is performed. The skip scan can always be used at the time of execution.
[0082]
Next, the processing operation of the analog television receiver 40 will be described. FIG. 4 is a flowchart for explaining the processing operation of the analog television receiver 40. This processing operation is repeatedly executed when the vehicle-mounted television apparatus 1 is turned on and reception of a predetermined analog broadcast is not instructed. As shown in FIG. 4, first, the analog television receiver 40 starts scanning an analog broadcast channel (step S101), and sets the first channel (for example, one channel) as a determination target for reception (step S102). .
[0083]
Next, the analog television receiver 40 determines whether or not the channel to be determined can be received (step S103), and if it can be received (step S104, Yes), it indicates that analog broadcasting is being performed on the channel. The information is stored in the table 43 (step S105) and notified to the digital television receiver 20 (step S106).
[0084]
After completion of step S106 or when reception is not possible (step S104, No), the analog television receiver 40 determines whether or not reception determination is completed for all channels in the frequency band (step S107).
[0085]
If there is a channel for which reception determination has not been completed yet (step S107, No), the analog television receiver 40 sets the next channel as a determination target (step S108), and determines whether or not the channel can be received (step S108). Step S103).
[0086]
On the other hand, if the determination is completed for all channels (step S107, Yes), the analog television receiver 40 ends the scanning process.
[0087]
As described above, when the vehicle-mounted television apparatus 1 is turned on and reception of a specific analog broadcast channel is not instructed, the analog television receiver 40 repeats scanning of the analog broadcast channel. It is possible to always keep the latest state and always use the skip scan when the digital television receiver 20 performs the scan.
[0088]
Next, the processing operation when the digital television receiver 20 performs scanning will be described. FIG. 5 is a flowchart for explaining the processing operation when the digital television receiver 20 executes scanning. As shown in FIG. 5, when receiving a digital broadcast channel scan request from the main control unit 11 (step S201), the digital television receiver 20 first sets the first channel as a determination target (step S202). .
[0089]
Thereafter, the digital television receiver 20 searches the analog broadcast channel table (step S203), and determines whether or not the channel to be determined is used for analog broadcast (step S204). If the determination target channel is not used for analog broadcasting (No in step S204), the digital television receiver 20 determines whether or not the channel can be received (step S205).
[0090]
If the digital broadcast can be received on the channel to be determined (step S206, Yes), the digital television receiver 20 stores in the channel table 23 that the digital broadcast is being performed on that channel (step S207).
[0091]
After step S207, if the digital broadcast cannot be received on the determination target channel (step S206, No), or if the determination target channel is used for analog broadcasting (step S204, Yes), the digital TV The receiver 20 determines whether or not reception permission determination has been completed for all channels in the frequency band (step S208).
[0092]
If there is a channel for which reception determination has not been completed yet (step S208, No), the digital television receiver 20 sets the next channel as a determination target (step S209), and whether the channel is used for analog broadcasting. It is determined whether or not (step S204). On the other hand, if the determination is completed for all channels (step S208, Yes), the digital television receiver 20 ends the process.
[0093]
The channel table of the analog broadcast channel referred to when scanning the digital broadcast channel may be the channel table 43 stored in the analog television receiver 40, or the analog broadcast channel table on the digital television receiver 20 side. You may remember it. When the analog television channel table is stored on the digital television receiver 20 side, when the analog television receiver 40 scans the analog broadcast channel, the scan result is received and stored in the digital television receiver 20. Keep it.
[0094]
By the way, when scanning a digital broadcast channel, if a non-broadcast channel in which neither an analog broadcast nor a digital broadcast is broadcast has been found, the determination of whether or not a non-broadcast channel can be received is skipped and the speed is further increased. be able to.
[0095]
Specifically, when the analog television receiver 40 performs scanning, the non-broadcast channel may be identified, and the non-broadcast channel may be stored in addition to the analog broadcast channel. FIG. 6 is an explanatory diagram for explaining a channel table storing non-broadcast channels. In the channel table 23c shown in the figure, 1 channel, 3 channels, 5 channels and 7 channels are stored as analog broadcast channels, 5 channels are stored as final viewing channels, and 4 channels are stored as non-broadcast channels. Yes.
[0096]
Therefore, when the digital television receiver 20 scans the digital broadcast channel, as shown in FIG. 7, it is determined whether or not the 2nd and 6th channels can be received excluding the analog broadcast channel and the non-broadcast channel.
[0097]
More specifically, the identification of the non-broadcast channel in the analog television receiver 40 is performed by comparing the average value output from the averaging processing unit 46 with a predetermined threshold value. It is determined that
[0098]
Scanning processing of the analog television receiver 40 when identifying a non-broadcast channel will be described with reference to FIG. FIG. 8 is a flowchart for explaining the processing operation of the analog television receiver 40 when identifying a non-broadcast channel. This processing operation is repeatedly executed when the vehicle-mounted television apparatus 1 is turned on and reception of a predetermined analog broadcast is not instructed. As shown in FIG. 8, first, the analog television receiver 40 starts scanning an analog broadcast channel (step S301), and sets the first channel (for example, one channel) as a determination target of whether or not reception is possible (step S302). .
[0099]
Thereafter, the analog television receiver 40 compares the average value output from the averaging processing unit 46 with a predetermined threshold value. If the reception intensity does not satisfy the threshold value (No in step S303), the channel is used for broadcasting. It is determined that there is no broadcast, that is, a non-broadcast channel (step S310).
[0100]
On the other hand, if the reception intensity is greater than or equal to the threshold (step S303, Yes), the analog television receiver 40 determines whether or not analog broadcast can be received on the channel (step S304).
[0101]
When the analog broadcast can be received on the channel (step S304, Yes), or when it is determined that the channel is a non-broadcast channel (step S310), the analog television receiver 40 determines whether the channel is an analog broadcast channel or The fact that it is a non-broadcast channel is recorded in the channel table 43 (step S305), and the digital television receiver 20 is notified (step S306).
[0102]
After step S306, or when analog broadcasting cannot be received (step S304, No), the analog television receiver 40 determines whether or not reception determination is completed for all channels in the frequency band (step S307). ).
[0103]
If there is a channel for which reception determination has not been completed yet (step S307, No), the analog television receiver 40 sets the next channel as a determination target (step S308), and determines whether or not the channel can be received (step S308). Step S303).
[0104]
On the other hand, if the determination is completed for all channels (step S307, Yes), the analog television receiver 40 ends the process.
[0105]
As described above, when the vehicle-mounted television apparatus 1 is turned on and reception of a specific analog broadcast channel is not instructed, the analog television receiver 40 repeats scanning of the analog broadcast channel and the non-broadcast channel. Therefore, the digital television receiver 20 can perform scanning while skipping the analog broadcasting channel and the non-broadcasting channel when scanning digital broadcasting.
[0106]
Next, the scanning operation of the digital television receiver 20 when skipping an analog broadcast channel and a non-broadcast channel will be described. FIG. 9 is a flowchart for explaining the processing operation when the digital television receiver 20 skips the analog broadcast channel and the non-broadcast channel. As shown in FIG. 9, when receiving a digital broadcast channel scan request from the main controller 11 (step S401), the digital television receiver 20 first sets the first channel as a determination target (step S402). .
[0107]
Thereafter, the digital television receiver 20 checks the channel table and determines whether or not the determination target channel is a non-broadcast channel (step S403). If the channel to be determined is not a non-broadcast channel (No at Step S403), the digital television receiver 20 checks the channel table and determines whether or not the channel is an analog broadcast channel (Step S404). When the determination target channel is an analog broadcast channel (step S404, No), the digital television receiver 20 determines whether or not the channel can be received (step S405).
[0108]
If the digital broadcast can be received on the determination target channel (step S406, Yes), the digital television receiver 20 records in the channel table that the channel is a digital broadcast channel (step S407).
[0109]
After step S407 is completed, if the digital broadcast cannot be received on the determination target channel (step S406, No), the determination target channel is an analog broadcast channel (step S404, Yes), or there is no determination target channel. If it is a broadcast channel (step S403), the digital television receiver 20 determines whether or not the reception enable / disable determination has been completed for all channels in the frequency band (step S408).
[0110]
If there is a channel for which reception determination has not been completed yet (step S408, No), the digital television receiver 20 sets the next channel as a determination target (step S409), and whether or not the channel is a non-broadcast channel. Is determined (step S403). On the other hand, if the determination is completed for all channels (step S408, Yes), the digital television receiver 20 ends the process.
[0111]
As described above, the digital television receiver 20 can scan the digital broadcast channel at a higher speed by skipping the analog broadcast channel and the non-broadcast channel.
[0112]
As described above, in the in-vehicle television device 1 shown in the first embodiment, the analog television receiver 20 repeatedly scans the analog broadcast while the digital television receiver 20 is receiving the digital broadcast. The broadcast channel table 43 is kept up-to-date, and when the digital television receiver 20 performs scanning, skip scanning excluding analog broadcast channels is executed, thereby speeding up scanning of the digital broadcast channels.
[0113]
Further, when the analog television receiver 40 performs scanning, it is determined that a channel whose reception intensity average value is less than the threshold is a non-broadcast channel, and when the digital television receiver 20 performs scanning, the analog broadcast channel and By performing skip scans that exclude non-broadcast channels, digital broadcast channel scans are further accelerated.
[0114]
In the first embodiment, the case where the digital broadcast scan is speeded up using the analog broadcast channel table has been described. However, the digital broadcast channel table may be used to speed up the analog broadcast scan. good.
[0115]
When the digital broadcast channel table is used for speeding up the scan of the analog broadcast, the digital TV receiver 40 repeatedly scans the digital broadcast while the analog TV receiver 40 is receiving the analog broadcast. When the channel table 23 is kept up-to-date and the analog television receiver 40 performs scanning, the digital broadcast channel may be excluded and skip scanning may be performed.
[0116]
Further, in the first embodiment, the speeding up in the case of scanning the digital broadcast channel has been described. However, even in the case of searching for the digital broadcast channel, similarly, the skip search excluding the analog broadcast channel is performed. Search can be speeded up.
[0117]
(Embodiment 2)
In the first embodiment described above, it is determined whether or not analog broadcasting is being performed on the channel based on the average value of the reception intensity. However, the method for determining the presence / absence of analog broadcasting is not limited to the method based on the average value of the reception intensity. In the second embodiment, another method for determining the presence / absence of analog broadcasting will be described.
[0118]
As a method for determining the presence or absence of analog broadcasting, for example, the amount of change in reception intensity can be used. FIG. 10 is a diagram illustrating a schematic configuration of an in-vehicle television apparatus that determines whether or not an analog broadcast can be received using the amount of change in reception intensity. As shown in the figure, the in-vehicle television device 1a includes a digital television receiver 20, an analog television receiver 60, a main control unit 11, a switching unit 12. It has a monitor 13.
[0119]
Here, since the configurations and operations of the digital television receiver 20, the main control unit 11, the switching unit 12, and the monitor 13 are the same as those of the in-vehicle television device 1 shown in the first embodiment, the same reference numerals are given. Description is omitted.
[0120]
The analog television receiver 60 includes an analog tuner 41, a CPU 42, a channel table 43, an IF detector 44, an amplifier 45, a change amount calculation unit 61, an AGC 47, and an analog demodulation unit 48 therein. The configurations and operations of the analog tuner 41, the CPU 42, the channel table 43, the IF detector 44, the amplifier 45, the AGC 47, and the analog demodulator 48 are the same as those of the in-vehicle television device 1 shown in the first embodiment, and therefore the same. The description is abbreviate | omitted and attached | subjected.
[0121]
The change amount calculation unit 61 calculates the change amount of the composite video signal output from the AGC 47 and outputs the change amount to the CPU 42. A schematic configuration of the change amount calculation unit 61 is shown in FIG. As shown in the figure, the change amount calculation unit 61 includes an absolute value circuit 61a and a delay circuit 61b. The delay circuit 61b delays the composite video signal by a predetermined amount. By calculating the difference between the delayed composite video signal and the original composite video signal and calculating the absolute value by the absolute value circuit 61a, the change amount of the composite video signal can be calculated.
[0122]
The CPU 42 compares the amount of change of the composite video signal with a predetermined threshold value, and determines that the broadcast can be received when the amount is less than the threshold value. In-vehicle TV equipment changes the radio wave reception intensity depending on the position of the vehicle. If the change in the composite video signal is below a certain level, it can be determined that the radio wave reception status is stable, and stable quality broadcasting is possible. You can receive.
[0123]
Further, the stability of the synchronization signal may be used as a method for determining the presence or absence of analog broadcasting. FIG. 12 is a diagram illustrating a schematic configuration of an in-vehicle television apparatus that determines whether analog broadcasting can be received using the stability of the synchronization signal. As shown in the figure, the in-vehicle television device 1b includes a digital television receiver 20, an analog television receiver 60a, a main control unit 11, a switching unit 12, and a monitor 13.
[0124]
Here, since the configurations and operations of the digital television receiver 20, the main control unit 11, the switching unit 12, and the monitor 13 are the same as those of the in-vehicle television device 1 shown in the first embodiment, the same reference numerals are given. Description is omitted.
[0125]
The analog television receiver 60a includes an analog tuner 41, a CPU 42, a channel table 43, an IF detector 44, an amplifier 45, an AGC 47, and an analog demodulation unit 48a. The configurations and operations of analog tuner 41, CPU 42, channel table 43, IF detector 44, amplifier 45, and AGC 47 are the same as in-vehicle television apparatus 1 shown in the first embodiment, and thus are denoted by the same reference numerals. The description is omitted.
[0126]
Analog demodulator 48a has sync separator 51, AFC 52, YC separator 53, and RGB demodulator 54 in the same manner as analog demodulator 48 shown in the first embodiment. Here, the analog demodulation unit 48 a outputs the output of the AFC 52 to the switching unit 12 and supplies it to the CPU 42.
[0127]
The CPU 42 monitors the period of the output (stabilized horizontal synchronization signal) of the AFC 52, and determines that analog broadcasting can be received if the period is constant. If the stabilized horizontal synchronization signal is stable in this way, it can be determined that the reception state of the radio wave is stable even when the vehicle is moving, and stable broadcast reception can be performed. it can.
[0128]
Further, the stability of the color subcarrier may be used as a method for determining the presence / absence of analog broadcasting. FIG. 13 is a diagram illustrating a schematic configuration of an in-vehicle television apparatus that determines whether or not an analog broadcast can be received using the stability of the color subcarrier. As shown in the figure, the in-vehicle television device 1c includes a digital television receiver 20, an analog television receiver 60b, a main control unit 11, a switching unit 12, and a monitor 13.
[0129]
Here, since the configurations and operations of the digital television receiver 20, the main control unit 11, the switching unit 12, and the monitor 13 are the same as those of the in-vehicle television device 1 shown in the first embodiment, the same reference numerals are given. Description is omitted.
[0130]
The analog television receiver 60b includes therein an analog tuner 41, a CPU 42, a channel table 43, an IF detector 44, an amplifier 45, an AGC 47, and an analog demodulator 48b. The configurations and operations of analog tuner 41, CPU 42, channel table 43, IF detector 44, amplifier 45, and AGC 47 are the same as in-vehicle television apparatus 1 shown in the first embodiment, and thus are denoted by the same reference numerals. The description is omitted.
[0131]
The analog demodulator 48b includes a sync separator 51, an AFC 52, a YC separator 53, an RGB demodulator 54, and a color burst averaging processor 62 therein. As shown in FIG. 14, the color burst averaging processing unit 62 includes an averaging processing unit 62a, an amplitude calculation unit 62b, and a burst extraction unit 62c.
[0132]
The burst extraction unit 62 c acquires a synchronization signal (burst gate pulse) from the AFC 52 and acquires a C signal (color signal) from the YC separation unit 53. The burst extraction unit 62a extracts the color burst signal (color subcarrier) included in the C signal at the timing of the burst gate pulse, and outputs it to the amplitude calculation unit 62b. The amplitude calculator 62b calculates the amplitude of the extracted color subcarrier and outputs it to the averaging processor 62a. The averaging processing unit 62a averages the amplitude value calculated by the amplitude calculating unit 62b for several lines and transmits the average value to the CPU.
[0133]
The CPU 42 determines that the analog broadcast can be received if the average value of the color subcarrier output from the color burst averaging processing unit 62 is equal to or greater than a certain threshold value. If the color subcarrier is stable in this way, it can be determined that the radio wave reception state is stable even when the vehicle is moving, and stable quality broadcast reception can be performed.
[0134]
As described above, in the in-vehicle television apparatuses 1a, 1b, and 1c shown in the second embodiment, the presence / absence of analog broadcasting is determined using the amount of change in reception intensity, the stability of the synchronization signal, and the stability of the color subcarrier. Can be determined.
[0135]
In Embodiment 2, the presence / absence of analog broadcasting is determined by using the amount of change in reception intensity, the stability of the synchronization signal, and the stability of the color subcarrier independently. The presence / absence of analog broadcasting may be determined using a combination of the stability of the synchronization signal, the stability of the color subcarrier, and the average value of the reception intensity shown in the first embodiment.
[0136]
(Embodiment 3)
In the first and second embodiments described above, the channel table is managed independently for each of the digital television receiver and the analog television receiver. However, the channel tables for analog broadcasting and digital broadcasting are managed collectively. It may be configured.
In the third embodiment, an in-vehicle television apparatus that collectively manages channel tables for analog broadcasting and digital broadcasting will be described. In the third embodiment, the control of the digital television receiver and the control of the analog television receiver are collectively performed by the main control unit.
[0137]
FIG. 15 is a schematic configuration diagram illustrating a schematic configuration of the in-vehicle television device according to the third embodiment. In FIG. 15, the in-vehicle television device 1 includes antennas 2 and 4, a digital television receiver 70, an analog television receiver 71, a main control unit 72, a switching unit 12, and a monitor 13.
[0138]
The digital television receiver 70 includes a digital tuner 21, a channel table 23, an MPEG decoder 24, and a digital demodulator 25 therein. The analog television receiver 71 includes an analog tuner 41, a channel table 43, an IF detector 44, an amplifier 45, an averaging processor 46, an AGC 47, and an analog demodulator 48 therein. Since the operation of these components is the same as that of the in-vehicle television device 1 shown in the first embodiment, the same reference numerals are given and description thereof is omitted.
[0139]
The main control unit 72 is a control unit that controls the vehicle-mounted television device 1 as a whole, controls the digital television receiver 20 and the analog television receiver 40, and controls the switching unit 12 to either digital broadcasting or analog broadcasting. Is displayed on the monitor 13. Here, the main control unit 72 can execute the processing performed by the CPUs 22 and 42 in the first embodiment. The main control unit 72 has a channel table 73 therein.
[0140]
The channel table 73 stores an analog broadcast channel and its final viewing channel, a digital broadcast channel and its final viewing channel. FIG. 16 shows a specific example of the channel table 73. In the channel table 73 shown in the figure, 1 channel, 3 channels, 5 channels, and 7 channels are stored as analog broadcast channels, and 3 channels are stored as final viewing channels of analog broadcasts. The channel table 73 stores 2 channels and 6 channels as digital broadcasting channels, and stores 6 channels as final viewing channels of digital broadcasting.
[0141]
The main controller 72 updates the channel table 73 by causing the analog television receiver 71 to scan the analog broadcast when the digital television receiver is receiving the digital broadcast. Further, when scanning a digital broadcast channel, high-speed scanning is realized by referring to the channel table 73 and skipping the analog broadcast channel.
[0142]
As in the first embodiment, the digital broadcast scan may be further accelerated by further searching for a non-broadcast channel and storing it in the channel table 73.
[0143]
By the way, which broadcast is performed on which channel in the frequency band is determined by the region. Therefore, the main control unit 72 stores the broadcast content table 75 as shown in FIG. 17, so that the broadcast content can be specified from the analog broadcast channel arrangement and the digital broadcast channel arrangement.
[0144]
For example, in the broadcast content table 75 shown in FIG. 17, in the region α, the analog A station for channel 1, the digital C station for channel 2, the analog B station for channel 3, the analog C station for channel 5, and the digital channel for channel 6 The analog D station is arranged in the A station and 7 channels. On the other hand, in the region β, an analog A station is arranged on the 2nd channel, a digital D station on the 3rd channel, an analog B station on the 4th channel, an analog C station on the 6th channel, and a digital D station on the 7th channel.
[0145]
Therefore, by referring to the broadcast content table 75, an appropriate channel can be selected and received according to the broadcast content designated by the user. Further, if the area can be identified as a result of the channel scan, the channel arrangement can be estimated without performing the scan thereafter. Furthermore, if it is possible to specify which region the host vehicle is traveling by using GPS or the like, the channel arrangement can be estimated.
[0146]
As described above, in the in-vehicle television device 1d shown in the third embodiment, the digital television receiver 70 and the analog television receiver 71 are collectively controlled by the main control unit 72, and the digital broadcasting channel and the analog broadcasting are controlled. Since the channels are collectively managed by the channel table 73 in the main control unit 72, the digital broadcast skip scan can be realized with a simple configuration.
[0147]
Furthermore, by storing in advance the arrangement of broadcast channels in each region, the scanning process can be further speeded up, and a channel corresponding to the designated broadcast content can be automatically selected and received.
[0148]
【The invention's effect】
As described above, according to the first aspect of the present invention, the receiving device searches for a channel on which analog broadcasting is performed from a frequency band, and selects a digital broadcasting channel selectively from a channel on which analog broadcasting is not performed. Since the search is performed, it is possible to obtain a receiving device capable of searching for a receivable channel at a high speed.
[0149]
According to a second aspect of the present invention, the receiving apparatus searches for an analog broadcast channel using the analog tuner while the digital tuner is receiving the digital broadcast, and the analog broadcast is used when searching for the digital broadcast channel. Since a search is performed from a channel that is not performed, an analog tuner can be used effectively, and a receiving device that can search a receivable channel at a high speed can be obtained.
[0150]
According to a third aspect of the present invention, the receiving device continuously searches for an analog broadcast channel using the analog tuner and searches for the digital broadcast channel while the digital tuner is receiving the digital broadcast. Since the search is performed from a channel on which no analog broadcast is performed, there is an effect that a receiving apparatus that always uses the latest analog broadcast channel and can search for a receivable channel at a high speed can be obtained.
[0151]
According to the invention of claim 4, the receiving device searches for an analog broadcast channel based on the average value of the received radio wave intensity, and selectively searches for a digital broadcast channel from channels where analog broadcasting is not performed. There is an effect that a receiving apparatus capable of easily searching for an analog broadcast channel and searching for a receivable digital broadcast channel at a high speed can be obtained.
[0152]
According to the invention of claim 5, the receiving device searches for an analog broadcast channel based on the amount of change in the received radio wave intensity, and selectively searches for a digital broadcast channel from channels where analog broadcasting is not performed. There is an effect that a receiving apparatus capable of searching for an analog broadcast channel that can be stably received and searching for a receivable digital broadcast channel at a high speed can be obtained.
[0153]
According to the sixth aspect of the present invention, the receiving device searches for the analog broadcast channel based on the stability of the synchronization signal, and selectively searches for the digital broadcast channel from the channels where the analog broadcast is not performed. Thus, there is an effect that a receiving apparatus capable of searching for a receivable analog broadcast channel and searching for a receivable digital broadcast channel at a high speed can be obtained.
[0154]
Further, according to the invention of claim 7, the receiving device searches for the analog broadcast channel based on the stability of the color subcarrier, and selectively searches for the digital broadcast channel from the channels where the analog broadcast is not performed. There is an effect that a receiving apparatus capable of searching for an analog broadcast channel that can be stably received and searching for a receivable digital broadcast channel at a high speed can be obtained.
[0155]
According to the eighth aspect of the present invention, when the analog tuner or the digital tuner is receiving a broadcast, the receiving apparatus does not broadcast either the analog broadcast or the digital broadcast using the tuner that does not receive the broadcast. Since the non-broadcast channel is detected and the non-broadcast channel is excluded when the tuner receiving the broadcast scans or searches, there is an effect that a receiving apparatus capable of searching for a receivable channel at higher speed can be obtained.
[0156]
According to the ninth aspect of the present invention, when the channel to be received by the digital tuner is designated and the digital broadcast is not performed on the designated channel, the receiving apparatus selects a digital broadcast channel near the designated channel. Since reception is performed, even if the vehicle moves, there is an effect that a receiving device that can always display the broadcast content when the tuner is switched can be obtained.
[0157]
According to the tenth aspect of the present invention, the receiving method searches for a channel on which analog broadcasting is performed from a frequency band and selectively searches for a digital broadcasting channel from a channel on which analog broadcasting is not performed. There is an effect that a receiving method capable of searching for possible channels at high speed can be obtained.
[0158]
According to the eleventh aspect of the present invention, in the receiving method, the analog broadcast is searched using the analog tuner while the digital tuner is receiving the digital broadcast, and the analog broadcast is searched when the digital broadcast channel is searched. Since a search is performed from a channel that has not been performed, an analog tuner can be used effectively, and a reception method capable of searching for a receivable channel at a high speed can be obtained.
[0159]
According to a twelfth aspect of the present invention, in the receiving method, when the digital tuner receives a digital broadcast, the search for the analog broadcast channel using the analog tuner is continuously repeated to search for the digital broadcast channel. Since the search is performed from a channel on which no analog broadcast is performed, there is an effect that a reception method capable of always using the latest analog broadcast channel and searching for a receivable channel at a high speed can be obtained.
[0160]
According to the invention of claim 13, the receiving method searches for an analog broadcast channel based on an average value of received radio wave intensity, and selectively searches for a digital broadcast channel from a channel where analog broadcasting is not performed. There is an effect that a reception method capable of easily searching for an analog broadcast channel and searching for a receivable digital broadcast channel at a high speed can be obtained.
[0161]
According to the invention of claim 14, the receiving method searches for an analog broadcast channel based on the amount of change in received radio wave intensity, and selectively searches for a digital broadcast channel from a channel where analog broadcasting is not performed. There is an effect that a receiving method capable of searching for an analog broadcast channel that can be stably received and searching for a receivable digital broadcast channel at a high speed can be obtained.
[0162]
According to the fifteenth aspect of the present invention, the receiving method searches for an analog broadcast channel based on the stability of the synchronization signal, and selectively searches for a digital broadcast channel from a channel where analog broadcasting is not performed. Thus, there is an effect that a receiving method capable of searching for a receivable analog broadcast channel and searching for a receivable digital broadcast channel at a high speed can be obtained.
[0163]
According to the sixteenth aspect of the present invention, the receiving method searches for an analog broadcast channel based on the stability of the color subcarrier, and selectively searches for a digital broadcast channel from channels where analog broadcasting is not performed. There is an effect that a receiving method capable of searching for an analog broadcast channel that can be stably received and searching for a receivable digital broadcast channel at a high speed can be obtained.
[0164]
According to the seventeenth aspect of the present invention, when the analog tuner or the digital tuner is receiving a broadcast, neither the analog broadcast nor the digital broadcast is broadcast using the tuner that does not receive the broadcast. Since a non-broadcast channel is detected and the non-broadcast channel is excluded when the tuner receiving the broadcast scans or searches, there is an effect that a reception method capable of searching for a receivable channel at a higher speed can be obtained.
[0165]
According to the eighteenth aspect of the present invention, when a channel to be received by the digital tuner is designated and digital broadcasting is not performed on the designated channel, a digital broadcasting channel near the designated channel is selected. Since reception is performed, even if the vehicle moves, there is an effect that a reception method capable of always displaying broadcast contents at the time of tuner switching is obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram illustrating a schematic configuration of an in-vehicle television device according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram for explaining a specific example of the channel table shown in FIG. 1;
3 is an explanatory diagram for explaining a digital broadcast scan in the in-vehicle television device shown in FIG. 1. FIG.
4 is a flowchart for explaining processing operations of the analog television receiver shown in FIG. 1;
FIG. 5 is a flowchart for explaining a processing operation when the digital television receiver shown in FIG. 1 executes a scan;
FIG. 6 is an explanatory diagram for explaining a channel table storing non-broadcast channels.
FIG. 7 is an explanatory diagram for explaining scanning excluding an analog broadcast channel and a non-broadcast channel.
FIG. 8 is a flowchart for explaining the processing operation of the analog television receiver when identifying a non-broadcast channel.
FIG. 9 is a flowchart for explaining a processing operation when the digital television receiver skips an analog broadcast channel and a non-broadcast channel.
FIG. 10 is a diagram illustrating a schematic configuration of an in-vehicle television apparatus that determines whether or not an analog broadcast can be received using a change amount of reception intensity.
11 is an explanatory diagram illustrating a schematic configuration of a change amount calculation unit illustrated in FIG. 10;
FIG. 12 is a diagram illustrating a schematic configuration of an in-vehicle television device that determines whether or not an analog broadcast can be received using the stability of a synchronization signal.
FIG. 13 is a diagram illustrating a schematic configuration of an in-vehicle television apparatus that determines whether or not an analog broadcast can be received using the stability of a color subcarrier.
14 is an explanatory diagram illustrating a schematic configuration of a color burst averaging processing unit illustrated in FIG. 13;
FIG. 15 is a schematic configuration diagram showing a schematic configuration of the in-vehicle television device according to the third embodiment.
16 is an explanatory diagram illustrating a specific example of the channel table 73 illustrated in FIG. 15. FIG.
FIG. 17 is an explanatory diagram illustrating a broadcast content table that stores channel arrangements for each region.
[Explanation of symbols]
1 In-vehicle TV equipment
2,3 antenna
11, 72 Main control unit
12 Switching section
13 Monitor
20,70 Digital TV receiver
21 Digital tuner
22,42 CPU
23, 23a, 23b, 23c, 43, 43a, 73 Channel table
24 MPEG decoder
25 Digital demodulator
31, 47 AGC
32 ADC
33 Data symbol readout section
34 Decoding processor
35 TS buffer
40, 60, 60a, 60b, 60c, 71 Analog television receiver
41 Analog tuner
44 IF detector
45 Amplifier
46 Averaging processor
48, 48a, 48b Analog demodulator
51 Sync separator
52 AFC
53 YC separator
54 RGB demodulator
61 Change calculation section
61a Absolute value circuit
61b Delay circuit
62 Color burst averaging processor
62a Averaging processing part
62b Amplitude calculation unit
62c burst extractor
73 Broadcast contents table

Claims (18)

A receiving device comprising an analog tuner for receiving an analog broadcast and a digital tuner for receiving a digital broadcast,
Analog broadcast search means for searching for an analog broadcast channel in which analog broadcast is performed from a predetermined frequency band,
Digital broadcast search means for searching for a digital broadcast channel in which digital broadcast is selectively performed from channels not used for analog broadcast based on the search result of the analog broadcast search means. A receiving device. 2. The receiving apparatus according to claim 1, wherein the analog broadcast search means searches for the analog broadcast channel using the analog tuner while the digital tuner is receiving a digital broadcast. The receiving apparatus according to claim 2, wherein the analog broadcast search means continuously repeats the search for the analog broadcast channel while the digital tuner is receiving a digital broadcast. The receiving apparatus according to claim 1, wherein the analog broadcast search unit determines whether or not analog broadcast is being performed based on an average value of received radio wave intensity. The receiving apparatus according to claim 1, wherein the analog broadcast search unit determines whether analog broadcasting is being performed based on a change amount of received radio wave intensity. The receiving apparatus according to claim 1, wherein the analog broadcast search unit determines whether analog broadcast is being performed based on a stability of a synchronization signal. The receiving apparatus according to claim 1, wherein the analog broadcast search unit determines whether analog broadcast is being performed based on the stability of the color subcarrier. Non-broadcast channel search means for detecting a non-broadcast channel in which neither analog broadcast nor digital broadcast is broadcast using a tuner that is not receiving broadcast when the analog tuner or the digital tuner is receiving broadcast. The receiving apparatus according to claim 1, further comprising: a non-broadcast channel excluded when the tuner receiving the broadcast performs a scan or a search. The digital tuner receives a digital broadcasting channel in the vicinity of the designated channel when a channel to be received by the digital tuner is designated and digital broadcasting is not performed on the designated channel. The receiving device according to any one of 1 to 8. A reception method using an analog tuner for receiving an analog broadcast and a digital tuner for receiving a digital broadcast,
An analog broadcast search step of searching for an analog broadcast channel in which analog broadcast is performed from a predetermined frequency band;
A digital broadcast search step of searching for a digital broadcast channel in which digital broadcast is selectively performed from channels not used for analog broadcast based on the search result of the analog broadcast search step. And the receiving method. The reception method according to claim 10, wherein the analog broadcast search step searches the analog broadcast channel using the analog tuner while the digital tuner is receiving the digital broadcast. 12. The receiving method according to claim 11, wherein the analog broadcast search step continuously repeats the search for the analog broadcast channel while the digital tuner is receiving the digital broadcast. The reception method according to claim 10, wherein the analog broadcast search step determines whether analog broadcast is being performed based on an average value of received radio wave intensity. The reception method according to claim 10, wherein the analog broadcast search step determines whether analog broadcast is being performed based on a change amount of received radio wave intensity. 15. The reception method according to claim 10, wherein the analog broadcast search step determines whether or not analog broadcast is being performed based on a stability of a synchronization signal. 16. The reception method according to claim 10, wherein the analog broadcast search step determines whether analog broadcast is being performed based on the stability of the color subcarrier. When the analog tuner or the digital tuner is receiving a broadcast, a non-broadcast channel search step of detecting a non-broadcast channel in which neither an analog broadcast nor a digital broadcast is broadcast using a tuner that does not receive the broadcast. The receiving method according to claim 10, further comprising: excluding the non-broadcast channel when the tuner receiving the broadcast performs a scan or a search. The digital tuner receives a digital broadcasting channel in the vicinity of the designated channel when a channel to be received by the digital tuner is designated and digital broadcasting is not performed on the designated channel. The reception method according to any one of 10 to 17.

Images