JP2008085762A - Digital broadcast receiver, and method and program for controlling digital broadcast receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital broadcast receiver capable of viewing different programs on monitors, which includes a plurality of monitors, and a method and a program for controlling the digital broadcast receiver. <P>SOLUTION: The digital broadcast receiver comprises a mode switching means for switching a first picture mode and a second picture mode. During the first picture mode, a synthetic diversity signal resulting from composing digital signals from both first and second receiving units 10 and 20 while regarding broadcast services received by the both as an identical service, and this synthetic diversity signal is reproduced by both first and second reproducing means. During the second picture mode, a digital signal obtained from the first receiving unit is decoded by a first decoding unit and reproduced by the second reproducing means, and a digital signal obtained from the second receiving unit is decoded by a second decoding unit and reproduced by the second reproducing means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a digital broadcast receiving apparatus for receiving a broadcast service of a digital broadcast, and a control method and control program for the digital broadcast receiving apparatus.

  In recent years, terrestrial digital broadcasting has been used in which a digital signal is modulated and transmitted from a terrestrial transmitting station, and demodulated and decoded on a receiver side to reproduce a broadcasting service such as video, audio, and data. Such terrestrial digital broadcasting can receive high-quality video, audio, data, and the like without using a large antenna such as a parabolic antenna, and therefore can be easily mounted on a mobile body such as an automobile.

In a mobile body in which seats such as passenger cars are arranged in a plurality of rows, it is desired that the broadcast service can be viewed from any seat. As what implement | achieved this subject, there exist some which are disclosed by patent document 1, for example. In the receiving apparatus described in Patent Document 1, a broadcast service can be viewed from any seat by arranging a monitor for each row of seats.
JP 2006-109044

  However, in the conventional configuration such as Patent Document 1, the same content video is displayed on all monitors, and for example, it is not possible to answer the request for watching different programs on the passenger seat and the rear seat. It was.

  SUMMARY OF THE INVENTION The present invention solves the above-described problem, and is a digital broadcast receiving device having a plurality of monitors, which is capable of viewing different programs on each monitor, and for controlling the digital broadcast receiving device. It is an object to provide a control method and program.

  In order to achieve the above object, the digital broadcast receiving apparatus according to the present invention is a combined diversity signal obtained by combining the digital signals from both broadcast services received by the first and second receiving units. The first screen mode in which both the first and second reproduction means reproduce the data and the digital signal obtained from the first receiving unit is decoded by the first decoding unit. Mode switching means for switching between a second screen mode that is reproduced by the second reproduction means and that the digital signal obtained from the second receiving unit is decoded by the second decoding unit and reproduced by the second reproduction means. Prepare.

  With such a configuration, it is possible to view a different program for each monitor by switching to the second screen mode. In the first screen mode, the broadcast service is received by combining diversity that can obtain a high-quality signal with few errors.

  In the second screen mode, when the broadcast services received by the first and second receiving units are the same as a result of selection by the broadcast service selection unit, the mode switching means switches to the first screen mode. It is good also as a structure.

  According to such a configuration, in the second screen mode, a user who is watching a program on one playback means switches a channel to a broadcast service that broadcasts a program being played on the other playback means. At the same time, it automatically shifts to the first screen mode, and it becomes possible to view a high-quality program by combining diversity.

  In addition, as a configuration further comprising data quality setting means for setting whether to obtain a high bit rate signal or a low bit rate signal for each of the first and second decoding units Also good. At this time, signal quality detection means for detecting the signal quality of the broadcast wave received by the first and second receiving units, and when the detected signal quality is higher than a predetermined level, a high bit rate signal is obtained, In addition, it is more preferable to further include a quality adjusting unit that controls the data quality setting unit so that a low bit rate signal can be obtained when the level is lower than the predetermined level.

  With such a configuration, high-quality broadcasting (for example, 12-segment broadcasting in terrestrial digital broadcasting) and broadcasting that can be expected to have good viewing even in low-quality but weak broadcast waves (for example, 1-segment broadcasting in terrestrial digital broadcasting) ) Is automatically switched according to the quality of the broadcast wave, and it is expected that the program can be viewed more satisfactorily.

  Here, the signal quality detection means detects, for example, the bit error rate of the signal demodulated in the first and second receiving units as the signal quality. Alternatively, the signal quality detection means detects the C / N ratio of the signal demodulated in the first and second receiving units as the signal quality.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an in-vehicle terrestrial digital broadcast receiving apparatus according to an embodiment of the present invention. As illustrated in FIG. 1, the receiving device 1 includes a first receiving unit 10 including a first antenna 11, a first tuner 12, and a first demodulator 13, a second antenna 21, a second tuner 22, and a second demodulator. A second receiving unit 20 including a unit 23, a first decoder 31, a second decoder 32, an output switching circuit 42, a first reproducing unit 51, a second reproducing unit 52, and a controller 60. . Here, the first and second playback units 51 and 52 include monitors 51a and 51b for displaying video, speakers 51b and 52b for outputting audio, and keypads 51c and 52c for selecting a channel, respectively. ing. The receiving device 1 of the present embodiment is assumed to be mounted on a passenger car. The first playback unit 51 is on the front seat (driver seat and passenger seat) side, and the second playback unit 52 is on the rear side. It is attached to the seat side. In FIG. 1, solid arrows indicate the flow of broadcast signals or data, and broken arrows indicate the flow of control between the controller 60 and other members.

  The first receiving unit 10 and the second receiving unit 20 can receive different broadcast services (reception frequency and subcarrier). The following description relates to the first receiving unit 10. The functions of the first antenna 11, the first tuner 12, and the first demodulator 13 are the same as those of the second antenna 21, the second tuner 22, and the second demodulator 23. Equivalent to function. A broadcast wave of digital broadcasting is received by the first antenna 11, and a signal in a desired frequency band is extracted by the first tuner 12 and transmitted to the first demodulator 13. In this embodiment, the digital broadcast signal is an analog signal modulated by the OFDM method, and is demodulated by the first demodulator 13 (A / D conversion, orthogonal demodulation, FFT conversion, waveform equivalent processing, and digital decoding) Process) to obtain a digital signal. The demodulated digital signal is transmitted to the first decoder 31.

  The first decoder 31 has a function of decoding encoded video / audio data (for example, MPEG2 system) included in the demodulated digital signal. The decoder 31 has a function of processing the decoded video data, converting it into a video signal of a predetermined format (an analog signal such as a component signal or a digital signal such as a DVI signal), and outputting the video signal. Further, the decoder 31 has a function of processing the decoded audio data, converting it into a predetermined format (analog or digital) audio signal, and outputting it. Note that the second decode 32 to which the digital signal demodulated by the second demodulator 23 is input also has the same function as the first decoder 31.

  The output of the first decoder 31 is sent to both the first reproducing unit 51 and the output switching circuit 42. The output of the second decoder 32 is sent only to the output switching circuit 42. The controller 60 controls the output switching circuit 42 to selectively output one of the video / audio data input from the first and second decoders 31 and 32 to the second reproduction unit 52. Yes. That is, in the present embodiment, the first screen mode in which the output of the first decoder 31 is reproduced by both the first and second reproduction units 51 and 52, and the output of the first decoder 31 is the first reproduction. And the second screen mode in which the output of the second decoder 32 is output by the second reproduction unit 52 can be switched. This switching operation is performed by operating either the keypad 51c of the first playback unit 51 or the keypad 52c of the second playback unit 52. That is, this switching operation can be performed from either the front seat side or the rear seat side.

  In the first screen mode, a broadcast service to be viewed can be selected on both the keypad 51c of the first playback unit 51 and the keypad 52c of the second playback unit 52. In this case, for example, when the broadcast service is changed on the front seat side, the broadcast service reproduced in the second reproduction unit 52 on the rear seat side is also switched. On the other hand, in the second screen mode, the broadcast service reproduced by the first reproduction unit 51 is selected by the keypad 51c of the first reproduction unit 51 and the broadcast service reproduced by the second reproduction unit 52. Is separately selected on the keypad 52c of the second playback unit 52. In this case, even if the broadcast service being played back by one playback unit is changed, the broadcast service being played back by the other playback unit does not change.

  In the present embodiment, so-called synthesis diversity in which the first reception unit 10 and the second reception unit 20 receive broadcast signals of the same broadcast service and synthesize them to generate a signal with few errors (data loss). Can be done. More specifically, the first receiving unit 10 and the second receiving unit 20 once demodulate the broadcast wave once, synthesize the obtained signals, and modulate again. The resulting signal is a high quality signal with fewer errors than the signals received by the first receiving unit 10 and the second receiving unit 20. This signal is demodulated again by the first demodulator 13 to obtain a high-quality digital signal. The synthesis diversity is executed in the first screen mode, obtained by the first receiving unit 10, and the video / audio data decoded by the first decoder 31 is both in the first reproduction unit 51 and the second reproduction unit 52. It is played with.

  The receiving apparatus 1 according to the present embodiment receives and reproduces digital broadcasts conforming to the ARIB standards TR-B14 and STD-B31. In this standard, one physical channel is divided into 13 segments. Of these 13 segments, 12 segments are used for high bit rate, that is, high-quality (HDTV quality) video / audio transmission (so-called 12-segment broadcasting), and at the same time, the remaining one segment is used for low-speed transmission. Bit rate, that is, low quality (QVGA quality) video / audio transmission (so-called 1-segment broadcasting) is performed. Compared with 12-segment broadcasting, 1-segment broadcasting can be received relatively well even when the reception state of radio waves is poor. It has the characteristic. Usually, so-called simulcasting is performed in which the same content is transmitted in 12-segment broadcasting and 1-segment broadcasting on the same physical channel.

  In the present embodiment, the controller 60 detects the quality of signals received / demodulated by the first and second receiving units 10 and 20, and switches between 12-segment broadcasting and 1-segment broadcasting according to the quality. It has become. The operation of the controller 60 including this configuration will be described below.

  In this embodiment, the user of the receiving apparatus 1 operates the keypad 51c of the first playback unit 51 or the keypad 52c of the second playback unit 52 to instruct switching of the screen mode, and then changes the broadcast service (so-called so-called). The screen mode is changed when an instruction to change the channel is issued. Therefore, the controller 60 uses the screen mode switching setting routine shown in the flowchart of FIG. 2 and the broadcast service switching routine shown in the flowchart of FIG.

  The screen mode switching setting routine of FIG. 2 is executed when the user of the receiving apparatus 1 operates the keypad 51c of the first playback unit 51 or the keypad 52c of the second playback unit 52 to instruct switching of the screen mode. Routine. When this routine is executed, step S1 is executed. In step S <b> 1, the content of the designated screen mode is confirmed by operating the keypad 51 c of the first reproduction unit 51 or the keypad 52 c of the second reproduction unit 52 by the user of the receiving device 1. That is, it is determined which one of the first screen mode and the second screen mode is selected by the user. If the first playback unit 51 and the second playback unit 52 are set to the first screen mode for playback of the same content broadcast service (S1: first screen mode), the process proceeds to step S2.

  In step S2, the reception mode flag is determined. The reception mode flag is a flag indicating whether reception is currently performed by combining diversity (diversity operation) or reception is performed without cooperation of each receiving unit (single operation). In step S2, when the value indicating that the single operation is performed is set in the reception mode flag (S2: single), the process proceeds to step S3.

  In step S3, a diversity switching process (described later) for starting the diversity operation is executed. After this processing is completed, step S4 is executed.

  On the other hand, if a value indicating that the diversity operation is being performed is set in the reception mode flag in step S2 (S2: diversity), it is not necessary to execute step S3, and the process proceeds to step S4.

  In step S4, a screen mode flag is set. The screen mode flag is a flag indicating whether the screen mode to be set is the first screen mode or the second screen mode. In step S4, a value indicating that the screen mode to be set is the first screen mode is set in the screen mode flag. Next, this routine ends.

  On the other hand, when the second screen mode for reproducing different broadcast services is set in the first reproduction unit 51 and the second reproduction unit 52 in step S1 (S1: second screen mode), step S5 is performed. Proceed to In step S5, a value indicating that the screen mode to be set is the second screen mode is set in the screen mode flag. Next, this routine ends.

  As described above, when this routine is executed, the screen mode flag is changed according to the content of the instruction from the user.

  Next, a broadcast service switching routine will be described. In the broadcast service switching routine shown in FIG. 3, the user changes the broadcast service received / reproduced by the user of the receiving device 1 operating the keypad 51c of the first reproduction unit 51 or the keypad 52c of the second reproduction unit 52. This routine is executed when an instruction is issued. When this routine starts, step S11 is executed.

  In step S11, the contents of the screen mode flag are confirmed. That is, when it is confirmed in step S11 that a value indicating that the screen mode to be set is the first screen mode is set in the screen mode flag (S11: first screen mode), Proceed to step S12.

  In step S12, a first channel selection process (described later) for changing the broadcast service received in the first screen mode is executed. Next, this routine ends.

  On the other hand, when it is confirmed in step S11 that the value indicating that the screen mode to be set is the second screen mode is set in the screen mode flag (S11: second screen mode), Proceed to step S13.

  In step S13, a second channel selection process (described later) for changing the broadcast service received in the second screen mode is executed. Next, this routine ends.

  Details of the first channel selection process executed in step S12 of the routine of FIG. 3 will be described below. FIG. 4 is a flowchart of this first tuning process routine. When the first channel selection process is executed, step S21 in the flowchart of FIG. 4 is executed.

  In step S21, the contents of the reception mode flag are confirmed. In this step, when the value indicating that the single operation is performed is set in the reception mode flag (S21: single), the process proceeds to step S22.

  In step S22, a diversity switching process (described later) for starting the diversity operation is executed. After this processing is completed, step S23 is executed.

  In step S21, when the value indicating that the diversity operation is performed is set in the reception mode flag (S21: diversity), it is not necessary to execute step S22, so the process proceeds to step S23.

  In step S23, the first and second tuners 12 and 22 are adjusted to the physical channel of the broadcast service designated by the user before the execution of the broadcast service switching routine (FIG. 3). Next, this routine is terminated.

  When the first channel selection process described above is executed, reception / playback of the broadcast service designated by the user is performed by combining diversity, and the broadcast service includes the first playback unit 51 and the second playback unit. 52 is reproduced.

  Details of the second channel selection process executed in step S13 of the routine of FIG. 3 will be described below. FIG. 5 is a flowchart of this second channel selection processing routine. When the second channel selection process is executed, step S31 of the flowchart of FIG. 5 is executed.

  This routine is executed when the user gives an instruction to change the broadcast service to be reproduced by the first reproduction unit 51 or the second reproduction unit 52. In step S31, there are a broadcast service to be played back in a playback unit for which a broadcast service change instruction is given by the user, and a broadcast service currently being played back in a playback unit for which the broadcast service change instruction is not given by the user. A determination is made as to whether they are identical. If the broadcast services are not the same (S31: NO), the process proceeds to step S32.

  In step S32, the reception mode flag is confirmed. When the value indicating that the diversity operation is performed is set in the reception mode flag (S32: diversity), the process proceeds to step S33.

  In step S33, a single switching process (described later) for starting a single operation is executed. After this process is completed, step S34 is executed.

  On the other hand, if a value indicating that the single operation is being performed is set in the reception mode flag in step S32 (S32: single), it is not necessary to execute step S33, and the process proceeds to step S34.

  In step S34, a determination is made as to which of the first reproduction unit 51 and the second reproduction unit 52 is the reproduction unit for which the broadcast service change instruction has been issued by the user. If an instruction to change the broadcast service to be played back by the first playback unit 51 is made (S34: first playback unit), the process proceeds to step S35, and the broadcast instructed by the user as to the physical channel received by the first tuner 12 Set to the physical channel of the service. Next, this routine ends.

  If it is confirmed in step S34 that an instruction to change the broadcast service reproduced by the second reproduction unit 52 has been made (S34: second reproduction unit), the process proceeds to step S36, and the physical received by the second tuner 22 is received. Set the channel to the physical channel of the broadcast service indicated by the user. Next, this routine ends.

  In step S31, the broadcast service to be reproduced in the reproduction unit for which the user instructs to change the broadcast service, and the broadcast service currently reproduced in the reproduction unit for which the user does not instruct to change the broadcast service. Are the same (S31: YES), the process proceeds to step S37.

  In step S37, the contents of the reception mode flag are confirmed. In this step, when the value indicating that the single operation is performed is set in the reception mode flag (S37: single), the process proceeds to step S38.

  In step S38, a diversity switching process (described later) for starting the diversity operation is executed. Step S39 is performed after this processing is completed.

  In step S37, when the value indicating that the diversity operation is performed is set in the reception mode flag (S37: diversity), it is not necessary to execute step S38, so the process proceeds to step S39.

  In step S39, the first and second tuners 12 and 22 are adjusted to the physical channel of the broadcast service designated by the user before the execution of the broadcast service switching routine (FIG. 3). Next, this routine is terminated.

  As described above, when this routine is executed, the broadcast service to be played back by the playback unit instructed to change the broadcast service by the user and the playback unit to which the broadcast service change instruction is not given by the user. When the broadcast services currently being played back are the same, higher quality video / audio is played back by combining diversity.

  Diversity switching processing for switching from single operation to diversity operation will be described below. FIG. 6 is a flowchart of a diversity switching process routine. As described above, this routine is called from steps S3 (FIG. 2), S22 (FIG. 4), and S38 (FIG. 5). When this routine starts, step S41 is executed.

  In step S41, the controller 60 controls the first demodulator 13 and the second demodulator 23 so that the synthesis diversity is performed. Specifically, the signal demodulated by the second demodulator 23 is sent to the first demodulator 13, and the signal is demodulated by the first demodulator 13 by the first demodulator 13. Signal is used to perform synthesis diversity. Next, the process proceeds to step S42.

  In step S 42, the controller 60 controls the output switching circuit 42 so that the output of the first decoder (that is, the video / audio obtained by combining diversity) is sent to the second playback unit 52. Next, the process proceeds to step S43.

  In step S43, a value indicating that the diversity operation is being performed is set in the reception mode flag. Next, this routine ends.

  As described above, when this routine is executed, the reception / playback of the broadcast service based on the combined diversity is started, and the video / audio with the same content is played back by the first playback unit and the second playback unit.

  A single switching process for switching from the diversity operation to the single operation will be described below. This routine is called from step S33 (FIG. 5). FIG. 7 shows a flowchart of a single switching process routine. When this routine starts, step S51 is executed.

  In step S51, the controller 60 controls the first demodulator 13 and the second demodulator 23 to perform a single operation in which the first receiving unit 10 and the second receiving unit 20 separately receive and demodulate broadcast waves. To be Specifically, the signal demodulated orthogonally by the second demodulator 23 is not sent to the first demodulator 13 so that synthesis diversity is not performed. Next, the process proceeds to step S52.

  In step S52, the controller 60 controls the output switching circuit 42 so that the output of the second decoder is sent to the second reproduction unit 52. Next, the process proceeds to step S53.

  In step S53, a value indicating that a single operation is being performed is set in the reception mode flag. Next, this routine ends.

  As described above, when this routine is executed, the signal received and decoded by the first receiving unit 10 is decoded by the first decoder and reproduced by the first reproduction unit 51, and the second reception is performed. The signal received and decoded by the unit 20 is decoded by the first decoder and reproduced by the second reproduction unit 52.

  In the present embodiment, the controller periodically checks the quality of the signal obtained by demodulation by the first demodulator 13 and the second demodulator 23, and according to the result, the low-quality one-segment broadcasting and Which of the high-definition 12-segment broadcasting should be reproduced is switched as appropriate. This broadcast switching process is executed by the routine shown in the flowchart of FIG. This routine is configured to operate in parallel with other routines shown in FIGS. In addition, this routine is executed periodically (for example, once per minute). When this routine is executed, step S101 is executed.

  In step S101, the decoding method of the first decoder 31, that is, whether the first decoder 31 is outputting video / audio of 1-segment broadcasting or video / audio of 12-segment broadcasting is checked. If the decoding method of the first decoder 31 is 1-segment broadcasting (S101: 1-segment), the process proceeds to step S102.

  In step S102, it is determined whether the signal quality of the output signal of the first demodulator 13 is equal to or higher than a reference level. This signal quality is performed, for example, depending on whether the bit error rate of the output signal is less than the first threshold value. If the bit error rate of the output signal is less than the first threshold, it is determined that the output signal is equal to or higher than the reference level, that is, a level at which 12-segment broadcasting can be sufficiently decoded. In such a case (S102: above the reference level), the process proceeds to step S103. Note that the output signal of the first demodulator 13 is obtained by demodulating the signal obtained as a result of the combined diversity during the combined diversity operation, and demodulates the signal received by the first receiving unit during the single operation. It is what. Therefore, this step determines the quality of the signal obtained as a result of the combining diversity during the combining diversity operation and the signal received by the first receiving unit during the single operation.

  In step S103, the decoding method by the first decoder 31 is set to 12-segment broadcasting. Next, the process proceeds to step S110.

  On the other hand, if the bit error rate of the output signal is greater than or equal to the first threshold value in step S102, it is determined that the output signal is less than the reference level, that is, a level at which 12-segment broadcasting cannot be sufficiently decoded. In such a case (S102: less than the reference level), the process proceeds to step S110 without executing step S103.

  If the decoding method of the first decoder 31 is 12-segment broadcasting in step S101 (S101: 12-segment), the process proceeds to step S104.

  In step S104, it is determined whether or not the signal quality of the output signal of the first demodulator 13 is less than the reference level. This signal quality is determined, for example, depending on whether the bit error rate of the output signal is greater than or equal to the second threshold value. If the bit error rate of the output signal is equal to or higher than the second threshold, it is determined that the output signal is less than the reference level, that is, the level at which 12-segment broadcasting cannot be sufficiently decoded. In such a case (S104: above the reference level), the process proceeds to step S105.

  In step S105, the decoding method by the first decoder 31 is set to 1-segment broadcasting. Next, the process proceeds to step S110. Note that the second threshold value is somewhat smaller than the first threshold value, and once the decoding method is 1-segment broadcasting, it is switched to 12-segment broadcasting until the quality of the output signal is sufficiently recovered. It does not change.

  On the other hand, if the bit error rate of the output signal is less than the second threshold value in step S104, it is determined that the output signal is equal to or higher than the reference level, that is, a level at which 12-segment broadcasting can be sufficiently decoded. In such a case (S104: above the reference level), the process proceeds to step S110 without executing step S105.

  In step S110, the reception mode flag is checked. When the value indicating that the single operation is performed is set in the reception mode flag (S110: single), the process proceeds to step S111.

  In step S111, the decoding method of the second decoder 32, that is, whether the second decoder 32 outputs video / audio of 1-segment broadcasting or video / audio of 12-segment broadcasting is checked. If the decoding method of the second decoder 31 is 1-segment broadcasting (S111: 1-segment), the process proceeds to step S112.

  In step S112, it is determined whether or not the signal quality of the output signal of the second demodulator 23 is equal to or higher than a reference level. This signal quality is performed, for example, depending on whether the bit error rate of the output signal is less than the first threshold value. If the bit error rate of the output signal is less than the first threshold, it is determined that the output signal is equal to or higher than the reference level, that is, a level at which 12-segment broadcasting can be sufficiently decoded. In such a case (S112: above the reference level), the process proceeds to step S113.

  In step S113, the decoding method by the second decoder 32 is set to 12-segment broadcasting. Next, this routine ends.

  On the other hand, if the bit error rate of the output signal is equal to or higher than the first threshold value in step S112, it is determined that the output signal is less than the reference level, that is, a level at which 12-segment broadcasting cannot be sufficiently decoded. In such a case (S112: less than the reference level), this routine is terminated without executing step S113.

  If the decoding method of the second decoder 32 is 12-segment broadcasting in step S111 (S111: 12-segment), the process proceeds to step S114.

  In step S114, it is determined whether or not the signal quality of the output signal of the second demodulator 23 is less than the reference level. This signal quality is determined, for example, depending on whether the bit error rate of the output signal is greater than or equal to the second threshold value. If the bit error rate of the output signal is equal to or higher than the second threshold, it is determined that the output signal is less than the reference level, that is, the level at which 12-segment broadcasting cannot be sufficiently decoded. In such a case (S114: above the reference level), the process proceeds to step S115.

  In step S115, the decoding method by the second decoder 32 is set to 1-segment broadcasting. Next, this routine ends.

  On the other hand, if the bit error rate of the output signal is less than the second threshold value in step S114, it is determined that the output signal is equal to or higher than the reference level, that is, a level at which 12-segment broadcasting can be sufficiently decoded. In such a case (S114: above the reference level), this routine is terminated without executing step S115.

  In addition, when the value indicating that the diversity operation is performed in step S110 is set in the reception mode flag (S110: diversity), since it is not necessary to set the decoding method of the second decoder, nothing is done. This routine is terminated.

  As described above, according to the present embodiment, the first screen mode for reproducing the same broadcast service by the front seat side playback unit and the rear seat side playback unit, the front seat side playback unit and the rear unit It is possible to switch the second screen mode for playing a different broadcast service by the seat-side playback unit by a user operation. In the first screen mode, it is possible to receive / reproduce a high-quality broadcast service by combining diversity. Furthermore, according to the present embodiment, high-quality 12-segment broadcasting is reproduced when a sufficiently high-quality broadcast wave is obtained, otherwise it is good even when the quality is low but the broadcast wave quality is low. One-segment broadcasting that can be played is played back.

  In the above-described embodiment, the first decoder 31, the second decoder 32, and the output switching circuit 42 are shown as separate components. However, the present invention is not limited to this configuration. Alternatively, a decoder element in which the first decoder 31, the second decoder 32, and the output switching circuit 42 are contained in one chip may be used.

  Also, in this embodiment, the criteria for determining whether to play a 12-segment broadcast service or to play a 1-segment broadcast service is received or demodulated by the first or second receiving unit. This is based on the bit error rate of the data. However, the present invention is not limited to the above configuration, and other determination criteria, for example, whether the C / N ratio of demodulated data is greater than or less than a predetermined value may be used.

  Further, in the present embodiment, even in the single operation, when the same broadcast service is selected by the first reproduction unit and the second reproduction unit, the configuration automatically shifts to the synthesis diversity operation. However, a single operation may always be used regardless of the broadcast service selected by the first reproduction unit and the second reproduction unit.

  Further, in the present embodiment, depending on the quality of the demodulated signal, whether to decode by 1-segment broadcasting or 12-segment broadcasting is appropriately changed, but the present invention is not limited to this configuration. . For example, the first screen mode that can be expected to improve the signal quality by combining diversity may always be decoded by 12-segment broadcasting, and in the second screen mode, it may be always decoded by 1-segment broadcasting.

  In the present embodiment, either one-segment broadcasting or 12-segment broadcasting is played back by both playback units during the synthesis diversity operation. However, the configuration of the output switching circuit or the decoder is changed. Thus, at the time of combining diversity operation, it is possible to reproduce 1 segment broadcasting by one reproducing unit and 12 segment broadcasting by the other reproducing unit. In addition, a configuration in which a power switch is provided in each of the playback units, and reception and playback of a broadcast service is performed by a combined diversity operation whenever only one playback unit is available is also within the scope of the present invention. Is within.

  In the present embodiment, two sets of configurations are disclosed for both the receiving unit and the playback unit, but the present invention is not limited to this configuration. That is, a configuration in which there are four sets of receiving units and three sets of reproducing units is also within the scope of the present invention. In this case, when all the playback units receive the same broadcast service, synthesis diversity is performed using all four reception units, and when each playback unit receives a different broadcast service, one playback unit receives 2 The signal obtained as a result of the combining diversity using the set of receiving units is reproduced, and the other two sets of reproducing units respectively reproduce the output from one set of receiving units. Alternatively, when each playback unit receives a different broadcast service, each of the three sets of playback units plays back the output from one set of receiving units (one receiving unit not involved in the playback of the broadcast service remains). Also good.

1 is a block diagram of an in-vehicle terrestrial digital broadcast receiver according to an embodiment of the present invention. It is a flowchart of the screen mode switching setting routine of an embodiment of the invention. It is a flowchart of the broadcast service switching routine of embodiment of this invention. It is a flowchart of the routine of the 1st channel selection process of embodiment of this invention. It is a flowchart of the routine of the 2nd channel selection process of embodiment of this invention. It is a flowchart of the routine of the diversity switching process of embodiment of this invention. It is a flowchart of the routine of the single switching process of embodiment of this invention. It is a flowchart of the routine of the broadcast switching process of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reception apparatus 10 1st receiving unit 11 1st antenna 12 1st tuner 13 1st demodulation part 20 2nd receiving unit 21 2nd antenna 22 2nd tuner 23 2nd demodulation part 31 1st decoder 32 2nd decoder 42 Output switching Circuit 51 First playback unit 51a Monitor 51b Speaker 51c Keypad 52 Second playback unit 52a Monitor 52b Speaker 52c Keypad

Claims (20)

First and second receiving units that receive and demodulate broadcast waves and output digital signals;
A combining diversity unit that combines the digital signals output from the first and second receiving units to generate a combined diversity signal;
A broadcast service selection unit for selecting a broadcast service to be received by the first and second reception units;
A first decoding unit that decodes the digital signal or the combined diversity signal output from the first receiving unit to extract a video, audio, and / or data signal;
A second decoding unit that decodes the digital signal output from the second receiving unit to extract a video and / or audio signal;
First and second reproduction means installed at different positions and reproducing the signals decoded by the first and second decoding units as video and / or audio;
The broadcast services received by the first and second receiving units are the same, and the combined diversity signal obtained by combining the digital signals from both is decoded, and the decoded signal is read by the first and second reproduction means. A first screen mode to be played back by both, and a digital signal obtained from the first receiving unit is decoded by a first decoding unit and played back by the first playback means, and the second receiving unit Mode switching means for switching between the second screen mode for decoding the digital signal obtained from the second decoding unit and reproducing the digital signal by the second reproduction means;
A digital broadcast receiver.   In the second screen mode, when the broadcast services received by the first and second receiving units are the same as a result of selection by the broadcast service selecting unit, the mode switching means is configured to display the first screen mode. The digital broadcast receiving apparatus according to claim 1, wherein the digital broadcast receiving apparatus is switched to.   The data quality setting means for setting whether to obtain a high bit rate signal or a low bit rate signal for each of the first and second decoding units. 3. The digital broadcast receiver according to 1 or 2. Signal quality detecting means for detecting signal quality of broadcast waves received by the first and second receiving units;
The data quality setting means is adapted to obtain a high bit rate signal when the detected signal quality is higher than a predetermined level, and to obtain a low bit rate signal when the detected signal quality is lower than the predetermined level. Quality adjustment means for controlling
The digital broadcast receiver according to claim 3, further comprising:   5. The digital broadcast receiving apparatus according to claim 4, wherein the signal quality detecting means detects a bit error rate of the signal demodulated in the first and second receiving units as the signal quality.   5. The digital broadcast receiving apparatus according to claim 4, wherein the signal quality detecting means detects a C / N ratio of signals demodulated in the first and second receiving units as the signal quality. First and second receiving units that receive and demodulate broadcast waves and output digital signals, and combined diversity that generates combined diversity signals by combining digital signals output from the first and second receiving units. A unit, a broadcast service selection unit for selecting a broadcast service to be received by the first and second reception units, a video by decoding the digital signal or the combined diversity signal output from the first reception unit, The first decoding unit that extracts the audio and / or data signal and the second decoding unit that decodes the digital signal output from the second receiving unit and extracts the video and / or audio signal are different from each other. The signal decoded by the first and second decoding units is reproduced as video and / or audio. That the first and second reproducing means, a control method for controlling a digital broadcast receiver having a,
The broadcast services received by the first and second receiving units are the same, and the combined diversity signal obtained by combining the digital signals from both is decoded and the decoded signal is read by the first and second reproduction means. A first screen mode to be played back by both, and a digital signal obtained from the first receiving unit is decoded by a first decoding unit and played back by the first playback means, and the second receiving unit; A control method for a digital broadcast receiving apparatus, comprising: a mode switching step for switching between a second screen mode in which a digital signal obtained from the above is decoded by a second decoding unit and reproduced by the second reproduction means.   In the second screen mode, when the broadcast services received by the first and second receiving units are the same as a result of selection by the broadcast service selection unit, the first screen mode is selected in the mode switching step. The method for controlling a digital broadcast receiving apparatus according to claim 7, wherein switching to is performed.   The method further comprises a data quality setting step for setting whether to obtain a high bit rate signal or a low bit rate signal for each of the first and second decoding units. The control method of the digital broadcast receiver as described in 7 or 8. A signal quality detecting step for detecting signal quality of broadcast waves received by the first and second receiving units;
The data quality setting means is adapted to obtain a high bit rate signal when the detected signal quality is higher than a predetermined level, and to obtain a low bit rate signal when the detected signal quality is lower than the predetermined level. Quality adjustment step to control,
The method for controlling a digital broadcast receiver according to claim 9, further comprising:   The control of the digital broadcast receiving apparatus according to claim 10, wherein the signal quality detecting step detects a bit error rate of a signal demodulated in the first and second receiving units as the signal quality. Method.   11. The digital broadcast receiving apparatus according to claim 10, wherein the signal quality detecting step detects a C / N ratio of signals demodulated in the first and second receiving units as the signal quality. Control method.   A control program for a digital broadcast receiving apparatus for causing the control method according to any one of claims 7 to 12 to be executed as a procedure. A receiving unit that receives and demodulates broadcast waves and outputs a digital signal;
A decoding unit that decodes a digital signal output from the receiving unit and extracts a video and / or audio signal;
A broadcast service selection unit for selecting a broadcast service to be received by the reception unit;
Data quality setting means for setting whether to obtain a high bit rate signal or a low bit rate signal from the decoding unit;
Signal quality detection means for detecting signal quality of broadcast waves received by the receiving unit;
The data quality setting means is adapted to obtain a high bit rate signal when the detected signal quality is higher than a predetermined level, and to obtain a low bit rate signal when the detected signal quality is lower than the predetermined level. Quality adjustment means for controlling
A digital broadcast receiver.   15. The digital broadcast receiving apparatus according to claim 14, wherein the signal quality detecting means detects a bit error rate of a signal demodulated in the receiving unit as the signal quality.   15. The digital broadcast receiving apparatus according to claim 14, wherein the signal quality detecting means detects a C / N ratio of a signal demodulated in the receiving unit as the signal quality. A receiving unit that receives and demodulates a broadcast wave and outputs a digital signal, a decoding unit that decodes the digital signal output from the receiving unit and extracts a video and / or audio signal, and a broadcast service received by the receiving unit A broadcast service selection unit for selecting a data quality setting means for setting whether to obtain a high bit rate signal or a low bit rate signal from the decoding unit. A control method for controlling a digital broadcast receiver,
A signal quality detection step of detecting the signal quality of the broadcast wave received by the receiving unit;
The data quality setting means is adapted to obtain a high bit rate signal when the detected signal quality is higher than a predetermined level, and to obtain a low bit rate signal when the detected signal quality is lower than the predetermined level. Quality adjustment step to control,
A method for controlling a digital broadcast receiving apparatus.   The method according to claim 17, wherein the signal quality detection step detects a bit error rate of a signal demodulated in the reception unit as the signal quality.   The method according to claim 17, wherein the signal quality detection means detects a C / N ratio of a signal demodulated in the reception unit as the signal quality.   A control program for a digital broadcast receiving apparatus for causing a control method according to any one of claims 17 to 19 to be executed as a procedure.

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