JP2010239538A - Converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a terrestrial digital broadcast receiver for converting video signals etc. of a program of terrestrial digital broadcast into analog television broadcast signals and transmitting the converted signals without interfering the reception of analog television broadcast in an analog television. <P>SOLUTION: The terrestrial digital broadcast receiver sets either a channel 1 or a channel 2 in analog television broadcast as a set channel, converts video signals etc. of a program of terrestrial digital broadcast into analog television broadcast signals corresponding to the set channel and transmits the converted signals. When it is detected that broadcast is performed with a channel not being the set channel out of the channel 1 or 2 (Yes in S520), a receiver switches the set channel into the other channel (S525), and converts the video signals etc. of the program of the terrestrial digital broadcast into broadcast signals corresponding to the set channel and transmits the converted signals. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a conversion apparatus that receives a digital television broadcast, generates a video signal, and converts the generated video signal or the like into a broadcast signal of an analog television broadcast.

  Since the analog television broadcast ends on July 24, 2011, after this date, the television program cannot be viewed on an analog television that supports only the analog television broadcast.

  Here, a tuner for digital terrestrial television broadcasting (hereinafter also referred to as terrestrial digital broadcasting) is externally attached to an analog television, and a video signal or the like output from this tuner is input to the analog television via a video terminal or the like. It has been proposed to view digital terrestrial broadcast programs using analog television.

  In addition, in-vehicle analog televisions are not provided with video input terminals (hereinafter referred to as video terminals), and there are many models in which a tuner for terrestrial digital broadcasting cannot be externally attached. A conversion device that enables viewing of a digital terrestrial broadcast program using such an analog television is described. This converter receives a terrestrial digital broadcast, generates a video signal and an audio signal, converts the generated signal into an analog television broadcast signal, and transmits the analog television broadcast signal. Then, by receiving the analog television broadcast signal transmitted from the conversion device, it is possible to view a terrestrial digital broadcast program on an in-vehicle analog television provided with no video terminal.

Registered Utility Model No. 3136154

  Here, the conversion device described in Patent Document 1 modulates a video signal or the like of a terrestrial digital broadcasting program into a signal having a frequency corresponding to an empty channel that is not broadcast among channels in analog television broadcasting. Is desirable. The reason is that by modulating the signal to such a frequency, it is possible to view all programs of the analog television broadcast on the analog television until the analog television broadcast is finished. However, in analog television broadcasting, a channel is uniquely set for each broadcasting area, and a different channel for each broadcasting area may be an empty channel. For this reason, even if a digital terrestrial broadcast video signal or the like is converted into an analog TV broadcast signal corresponding to an empty channel, the empty channel fluctuates due to a change in the broadcasting area where the conversion device exists, May interfere with the viewing of analog TV broadcasts.

  The present invention has been made in view of the above problems, and converts a video signal of a digital TV broadcast program into a broadcast signal of an analog TV broadcast without interfering with the reception of the analog TV broadcast by a receiving apparatus such as an analog TV. It is an object of the present invention to provide a conversion device that can transmit data.

The invention according to claim 1, which has been made to achieve the object,
A conversion device for receiving an analog television broadcast signal and a digital television broadcast signal,
Extraction means for extracting a video signal and an audio signal corresponding to a digital television broadcast channel designated by the user from the received digital television broadcast signal;
Determination means for determining whether analog TV broadcasting is being performed based on the state of the received analog TV broadcast signal for a determination target channel among channels in analog TV broadcast;
The channel determined that broadcasting is not performed by the determining means is an empty channel, and the signal generated by the extracting means is converted into an analog TV broadcast signal having a frequency corresponding to the empty channel in analog TV broadcasting, Conversion means for transmitting the converted analog TV broadcast signal to a receiving device for viewing the analog TV broadcast;
It is characterized by providing.

The invention according to claim 2 is the conversion device according to claim 1,
The converter is connected to an antenna unit capable of receiving digital TV broadcast radio waves and analog TV broadcast radio waves, and receives analog TV broadcast signals and digital TV broadcast signals from the antenna unit,
The converting means transmits the modulated signal to the receiving device via the antenna unit.

The invention described in claim 3 is the conversion device according to claim 1 or 2, wherein
The determination target channel is composed of a plurality of channels set as the vacant channels in different broadcast areas.

The invention according to claim 4 is the conversion device according to any one of claims 1 to 3,
The determination means includes
A BPF (Band Pass Filter) for extracting a signal in a frequency band corresponding to the determination target channel from the received analog television broadcast signal;
Based on the signal that has passed through the BPF, it is determined whether analog television broadcasting is being performed on the specific target channel.

Further, the invention according to claim 5 is the conversion device according to claim 3 or 4, wherein
The determination target channel is composed of a first channel and a second channel adjacent to each other,
The determination means determines whether analog TV broadcasting is being performed for the second channel when the first channel is the empty channel by the conversion means;
When the determination means determines that the analog TV broadcast is not being performed on the second channel, the conversion means replaces the first channel with the second channel instead of the first channel. It is characterized by being a channel.

  In the conversion device according to claim 1, the video signal and the audio signal corresponding to the channel designated by the user are extracted from the digital television broadcast signal by the extraction unit, and the determination target channel is analog for the channel to be determined. Based on the state of the television broadcast signal, it is determined whether broadcasting is being performed. Then, the conversion means converts the signal extracted by the extraction means into a signal having a frequency corresponding to an empty channel, and transmits the signal to a receiving apparatus for viewing analog television broadcasting. The receiving device may be, for example, an analog television.

By doing so, the conversion device can convert a video signal or an audio signal of a digital television broadcast program into a broadcast signal corresponding to an empty channel and transmit it to the reception device. Therefore, the conversion device according to claim 1 converts a video signal or the like of a digital television broadcast program into an analog television broadcast signal without interfering with reception of the analog television broadcast by the reception device such as an analog television. Can be sent to.

  In the conversion device according to claim 2, the analog television broadcast signal and the digital television broadcast signal are received from the antenna unit, and the conversion unit transmits the modulated signal to the reception device via the antenna unit. To do.

  By doing so, it is possible to transmit an analog television broadcast signal for viewing a digital television broadcast from the conversion device to the reception device without connecting the conversion device and the reception device with a transmission line such as a coaxial cable. Therefore, the conversion device can be installed more easily.

In addition, the area where the analog television broadcast can be received is divided into a plurality of broadcast areas, and a channel is uniquely set for each broadcast area.
Therefore, in the conversion device according to the third aspect, the determination target channel is composed of a plurality of channels set as vacant channels in different broadcast areas.

  In this way, regardless of the broadcasting area where the conversion device is present, any of the determination target channels becomes an empty channel. Therefore, for example, even when a conversion device is mounted on a vehicle, and this vehicle enters a new broadcasting area, and a vacant channel is changed to another channel, a video signal of a digital television broadcast program, etc. Thus, it is possible to convert to a broadcast signal corresponding to a new empty channel.

  In the conversion device according to claim 4, the determination unit further includes a BPF that extracts a signal in a frequency band corresponding to the determination target channel from the analog television broadcast signal, and broadcasts based on the signal that has passed through the BPF. Determine whether or not

  By doing so, it is possible to determine whether or not there is a broadcast on the determination target channel with a simpler configuration than when a signal corresponding to the determination target channel is extracted using a tuner for analog television broadcasting.

  Also, in the broadcasting area in analog TV broadcasting, one of the even channel and odd channel is generally set as an empty channel, and in the two adjacent broadcasting areas, the even channel is set as an empty channel. On the other hand, odd channels are set as empty channels. For this reason, in any broadcasting area, one of the adjacent channels is always considered to be an empty channel.

  Therefore, in the conversion device according to the fifth aspect, the determination target channel is composed of a first channel and a second channel adjacent to each other, and the determination means sets the first channel as an empty channel. In such a case, the presence or absence of analog television broadcasting is determined for the second channel, and if the broadcasting is not performed on the second channel, the conversion means replaces the first channel with the second channel. Is an empty channel.

By doing so, for example, even when the conversion device is mounted on a vehicle, the vehicle enters a new broadcasting area, and an empty channel is switched from an even channel to an odd channel (or vice versa) A signal obtained by converting a video signal or the like of digital television broadcasting can be automatically switched to a signal corresponding to a new empty channel.

It is a block diagram which shows the structure of the system which has a terrestrial digital broadcasting receiver. It is a block diagram which shows the structure of a terrestrial digital broadcasting receiver. It is a flowchart about a setting channel switching process. It is a block diagram which shows the structure of a terrestrial digital broadcasting receiver.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments of the present invention are not limited to the following embodiments, and various forms can be adopted as long as they belong to the technical scope of the present invention.

[Description of configuration]
FIG. 1 is a block diagram showing a configuration of a system having a terrestrial digital broadcast receiving apparatus 100 according to the present embodiment. This system is mounted on a vehicle, and the terrestrial digital broadcast receiving apparatus 100 is connected to a terrestrial digital antenna 200 capable of receiving radio waves in the VHF band and the UHF band via a transmission line such as a coaxial cable. . The system further includes an analog broadcast antenna 400 capable of receiving radio waves of VHF band and UHF band and AM and FM radio broadcasts, and is connected to the antenna. And an audio 300 capable of listening to a radio broadcast. Note that the terrestrial digital antenna 200 and the analog broadcast antenna 400 are arranged close to each other. These antennas may be film antennas that are affixed to the windows of the vehicle, and if these antennas are film antennas, they may be affixed to any of the windows in an overlaid state.

  Next, the configuration of the terrestrial digital broadcast receiving apparatus 100 will be described with reference to the block diagram shown in FIG. The terrestrial digital broadcast receiving apparatus 100 receives a connector 110 to which a transmission line connected to the terrestrial digital antenna 200 is connected, and a received signal from the connector 110, and cuts off the upper limit frequency of the VHF band on the low frequency side. And a diplexer 120 having the lower limit frequency of the UHF band as a cutoff frequency on the high frequency side.

  Also, the terrestrial digital broadcast receiving apparatus 100 demodulates a high-frequency side received signal (terrestrial digital broadcast signal) that has passed through the diplexer 120, and a video signal corresponding to a channel designated by the user via a remote controller (not shown). The terrestrial digital tuner unit 130 for extracting the audio signal, and the carrier wave corresponding to the channel (hereinafter also referred to as a set channel) designated by the control unit 180 based on the video signal and the audio signal extracted by the terrestrial digital tuner unit 130 And a modulation circuit 140 that generates an analog television broadcast signal in the VHF band.

  The terrestrial digital broadcast receiving apparatus 100 receives a low-frequency received signal (VHF band analog television broadcast signal) that has passed through the diplexer 120 and a directional coupler 150. An extraction unit 160 that extracts a signal corresponding to one of channels 1 and 2 from the analog television broadcast signal, a detection circuit 170 that detects the analog television broadcast signal extracted by the extraction unit 160, and a detection in the detection circuit 170 And a control unit 180 having a known CPU, ROM, RAM, and the like.

  The analog television broadcast signal generated by the modulation circuit 140 is input to the directional coupler 150, and is output from the connector 110 to the terrestrial digital antenna 200 via the diplexer 120.

  Next, the configuration of the extraction unit 160 will be described. The extraction unit 160 distributes the analog television broadcast signal from the directional coupler 150, and one of the analog television broadcast signals distributed by the distribution circuit 161 has a frequency band signal corresponding to channel 1. BPF 162 (Band Pass Filter) that passes only the signal, amplifier circuit 163 that amplifies the signal that has passed through BPF 162, and the other analog TV broadcast signal distributed by distribution circuit 161, in the frequency band corresponding to channel 2 It has a BPF 164 that allows only the signal to pass through, and an amplifier circuit 165 that amplifies the signal that has passed through the BPF 164. The extraction unit 160 also outputs one of the signal amplified by the amplification circuit 163 corresponding to the channel 1 and the signal amplified by the amplification circuit 165 corresponding to the channel 2 in accordance with an instruction from the control unit 180. A switching circuit 166 is input to the detection circuit 170.

[Description of operation]
Next, the operation of the terrestrial digital broadcast receiving apparatus 100 will be described. The terrestrial digital broadcast receiving apparatus 100 receives a terrestrial digital broadcast signal and an analog television broadcast signal from the terrestrial digital antenna 200, and from the received terrestrial digital broadcast signal to a channel designated by the user via a remote controller (not shown). Corresponding video and audio signals are extracted. Then, using either channel 1 or 2 as a setting channel, the extracted video signal or the like is converted into an analog television broadcast signal corresponding to the setting channel, and is transmitted to the audio 300 via the terrestrial digital antenna 200. In addition, the terrestrial digital broadcast receiving apparatus 100 executes a setting channel switching process at a regular timing while an analog television broadcast signal for viewing terrestrial digital broadcasting is being transmitted. Here, the setting channel switching process will be described with reference to the flowchart shown in FIG.

  In S505, in the terrestrial digital broadcast receiving apparatus 100, the control unit 180 determines whether or not the setting channel is channel 1. When the setting channel is channel 1 (S505: Yes), the control unit 180 shifts the process to S510, and when the setting channel is channel 2 (S505: No), the control unit 180 shifts the process to S515. .

  In S <b> 510, the control unit 180 instructs the switching circuit 166 to input the reception signal corresponding to channel 2 that is not the setting channel to the detection circuit 170. The detection circuit 170 detects the received signal corresponding to channel 2 and inputs the obtained signal to the control unit 180.

  On the other hand, in S515 that is shifted when the setting channel is channel 2, the control unit 180 instructs the switching circuit 166 to input the reception signal corresponding to channel 1 to the detection circuit 170. The detection circuit 170 detects the received signal corresponding to the channel 1 and inputs the obtained signal to the control unit 180.

  Subsequently, in S520, based on the level of the input signal from the detection circuit 170, the control unit 180 determines whether an analog television broadcast program is being broadcast on the channel corresponding to this signal. Specifically, when the level of the input signal is less than a predetermined threshold, it is considered that an analog television broadcast program is not broadcast on the corresponding channel. When the program is not broadcast (S520: Yes), the control unit 180 switches the setting channel to the other channel, and the modulation circuit 140 performs a new operation based on the video signal from the terrestrial digital tuner unit 130 or the like. Instructs modulation of the carrier wave corresponding to the setting channel. Then, the control unit 180 ends this process.

  When the program is broadcast on the channel corresponding to the input signal from the detection circuit 170 (S520: No), the control unit 180 ends this process without switching the setting channel.

[effect]
In the terrestrial digital broadcast receiving apparatus 100 according to the present embodiment, one of the channels 1 and 2 is set as a set channel, and a digital TV broadcast video signal or the like is converted into an analog TV broadcast signal corresponding to the set channel and the audio 300 Sent to. Then, it is determined whether or not a channel that is not a setting channel among channels 1 and 2 is an empty channel. If this channel is an empty channel, the setting channel is replaced.

  For this reason, even when a vehicle equipped with the terrestrial digital broadcast receiving device 100 enters a new broadcasting area and an empty channel is switched from an even channel to an odd channel (or vice versa), automatically, A new empty channel can be set as a setting channel. Therefore, even when the vehicle enters a new broadcasting area, it is possible to convert a video signal of a digital TV broadcast program into an analog TV broadcast signal corresponding to a new empty channel. Therefore, it is possible to convert a video signal or the like of a digital television broadcast program into an analog television broadcast signal and transmit it to the audio 300 without hindering reception of the analog television broadcast in the audio 300.

  In addition, in the extraction unit 160 in the terrestrial digital broadcast receiving apparatus 100, signals corresponding to the channels 1 and 2 are extracted by the BPF, and the presence / absence of broadcasting is determined based on the level of this signal. For this reason, for example, it is possible to determine whether or not there is a broadcast on channel 1 or 2 with a simpler configuration than when signals corresponding to channels 1 and 2 are extracted using an analog tuner.

[Other Embodiments]
(1) In this embodiment, the extraction unit 160 of the terrestrial digital broadcast receiving apparatus 100 includes a BPF 162 that extracts a reception signal corresponding to channel 1, a BPF 164 that extracts a reception signal corresponding to channel 2, and the like. . However, the extraction unit 160 may include an analog tuner unit 167 and the like instead of these BPFs and the like as illustrated in FIG. Then, the analog tuner unit 167 extracts a received signal corresponding to the channel according to the instruction of the control unit 180 from the received signals from the directional coupler 150, and the extracted signal passes through the amplifier circuit 168 and is a detection circuit. You may output to 170. Even in such a configuration, the control unit 180 can determine whether or not broadcasting is being performed on a predetermined channel, and the video signal or the like from the terrestrial digital tuner unit 130 can be transmitted. It can be converted into an analog television broadcast signal corresponding to a channel that is not performed. Therefore, the same effect can be obtained.

  (2) In this embodiment, one of channels 1 and 2 in analog television broadcasting is set as a set channel, but the same processing is performed on two adjacent channels in the VHF band other than channels 1 and 2. You can go. Even if it has such a structure, the same effect can be acquired.

  (3) The terrestrial digital broadcast receiving apparatus 100 according to the present embodiment notifies the user that the setting channel has been changed and the new setting channel via, for example, a speaker (not shown) after changing the setting channel. Good. By doing so, the user can change the reception channel of the analog television broadcast in the audio 300 in accordance with the change of the setting channel, and the convenience of the terrestrial digital broadcast reception device 100 can be improved.

[Correspondence with Claims]
The correspondence between the terms used in the description of the above embodiment and the terms used in the description of the claims is shown.

The terrestrial digital broadcast receiving device 100 corresponds to a conversion device, the terrestrial digital antenna 200 corresponds to an antenna unit, and the audio 300 corresponds to a receiving device.
The terrestrial digital tuner unit 130 corresponds to an extraction unit, the modulation circuit 140 corresponds to a conversion unit, and the control unit 180 corresponds to a determination unit.

  Also, channels 1 and 2 in analog television broadcasting correspond to determination target channels, channel 1 corresponds to the first channel, and channel 2 corresponds to the second channel.

  DESCRIPTION OF SYMBOLS 100 ... Terrestrial digital broadcasting receiver, 110 ... Connector, 120 ... Diplexer, 130 ... Terrestrial digital tuner part, 140 ... Modulation circuit, 150 ... Directional coupler, 160 ... Extraction part, 161 ... Distribution circuit, 162 ... BPF, 163 ... Amplification circuit, 164 ... BPF, 165 ... Amplification circuit, 166 ... Switching circuit, 167 ... Analog tuner unit, 168 ... Amplification circuit, 170 ... Detection circuit, 180 ... Control unit, 200 ... Terrestrial digital antenna, 300 ... Audio, 400: Analog broadcasting antenna.

Claims (5)

A conversion device for receiving an analog television broadcast signal and a digital television broadcast signal,
Extraction means for extracting a video signal and an audio signal corresponding to a digital television broadcast channel designated by the user from the received digital television broadcast signal;
Determination means for determining whether analog TV broadcasting is being performed based on the state of the received analog TV broadcast signal for a determination target channel among channels in analog TV broadcast;
The channel determined as not being broadcast by the determination means is an empty channel, and the signal extracted by the extraction means is converted into an analog TV broadcast signal having a frequency corresponding to the empty channel in the analog TV broadcast, Conversion means for transmitting the converted analog TV broadcast signal to a receiving device for viewing the analog TV broadcast;
A conversion device comprising: The conversion device according to claim 1,
The converter is connected to an antenna unit capable of receiving digital TV broadcast radio waves and analog TV broadcast radio waves, and receives analog TV broadcast signals and digital TV broadcast signals from the antenna unit,
The converting means transmits the modulated signal to the receiving device via the antenna unit;
A conversion device characterized by. The conversion device according to claim 1 or 2,
The determination target channel is composed of a plurality of channels that are set as the empty channels in different broadcast areas,
A conversion device characterized by. The conversion device according to any one of claims 1 to 3,
The determination means includes
A BPF (Band Pass Filter) for extracting a signal in a frequency band corresponding to the determination target channel from the received analog television broadcast signal;
Determining whether analog TV broadcasting is being performed on the specific target channel based on the signal passing through the BPF;
A conversion device characterized by. In the conversion device according to claim 3 or 4,
The determination target channel is composed of a first channel and a second channel adjacent to each other,
The determination means determines whether analog TV broadcasting is being performed for the second channel when the first channel is the empty channel by the conversion means;
When the determination means determines that the analog TV broadcast is not being performed on the second channel, the conversion means replaces the first channel with the second channel instead of the first channel. A channel,
A conversion device characterized by.

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