JP2002171493A - Broadcast system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a broadcast system that can sufficiently reduce the power consumption of a terminal in a standby state and start the terminal so as to receive distribution information occasionally sent from a center device in the standby state. SOLUTION: The center device superimposes a start signal on a television broadcast signal within a transmission band of a prescribed analog channel among analog channels. The terminal includes a normal operation section to which an output voltage of a power supply circuit is applied at all times and of a start operation section to which no output voltage of the power supply circuit is applied in the standby state. When the normal operation section receives the television broadcast signal from the center device through the prescribed analog channel in the standby state and extracts the start signal from the received television broadcast signal, the normal operation section applies the output voltage of the power supply circuit to the start operation section to activate the start operation section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to transmitting broadcast information from a broadcast center device (hereinafter, referred to as a center device) to a terminal device separately from a television broadcast signal, and the terminal device responds to the broadcast information even in a standby state. Related to broadcasting systems.

[0002]

2. Description of the Related Art In a CATV broadcasting system, a plurality of television broadcast signals are sent from a center device to each terminal device via a cable, and each terminal device receives the television broadcast signal and transmits a desired television broadcast signal. The output is selectively performed to a television receiver.

When the terminal device is turned off in response to an operation by a user, the terminal device stops supplying a television broadcast signal to the television receiver, turns off the power of the television receiver itself, and shifts to a standby state. It is supposed to.
In the standby state, the power supply to all internal circuits is not stopped in the standby state, but reception contract renewal data and emergency broadcast reception instruction data transmitted separately from the television broadcast signal from the center device via a cable. Etc. can be received. That is, in the standby state, power is supplied to some internal circuits of the terminal device so that the distribution information can be received and stored in the internal memory or the television receiver can be started up. is there.

Accordingly, the terminal device always consumes a considerable amount of power even in the standby state. Therefore, the distribution information is transmitted from the center device to the terminal device only for a predetermined time period. 2. Description of the Related Art A system for reducing power consumption of a terminal device in a standby state by supplying power to an internal circuit is known (for example, Japanese Patent Application Laid-Open No. 200-200200).
0-308030).

[0005]

However, in such a conventional system, it is possible to cope with the transmission of the distribution information on a regular basis, but the distribution information such as command data for emergency broadcast reception which is transmitted irregularly. It is impossible to sufficiently cope with reception in the standby state. Therefore, an object of the present invention is to sufficiently reduce the power consumption of the terminal device in the standby state and activate the terminal device so as to receive irregular distribution information sent from the center device in the standby state. To provide a broadcasting system.

[0006]

A broadcast system according to the present invention is a broadcast system for transmitting an analog television broadcast signal to a terminal device through a plurality of analog channels from a center device, wherein the center device transmits a plurality of analog channels. The terminal device has a superimposing unit that superimposes a start signal in a transmission band of a television broadcast signal of a predetermined analog channel, wherein the terminal device includes a constantly operating unit to which an output voltage of a power supply circuit is constantly supplied, and a terminal device in a standby state. A start-up operation unit to which the output voltage of the power supply circuit is not supplied, wherein the constant operation unit is configured to receive a television broadcast signal from the center device on a predetermined analog channel when in a standby state;
Extraction means for extracting a start signal from a television broadcast signal received by the reception means, and control for operating the start operation section by supplying an output voltage of the power supply circuit to the start operation section when the start signal is extracted by the extraction means Means.

[0007] The center device of the present invention is a center device for transmitting analog television broadcast signals to a terminal device on a plurality of analog channels, and includes a transmission band for a television broadcast signal of a predetermined analog channel among the plurality of analog channels. It is characterized by having a superimposing means for superimposing a start signal therein. A terminal device according to the present invention is a terminal device that receives an analog television broadcast signal transmitted from a center device on a plurality of analog channels, and includes a constantly operating unit to which an output voltage of a power supply circuit is constantly supplied, and a standby state. A start-up operation unit to which the output voltage of the power supply circuit is not supplied at one time; a constant operation unit that receives a television broadcast signal from the center device on a predetermined analog channel when in a standby state; (1) Extracting means for extracting a start signal from a television broadcast signal received by a receiving means, and supplying an output voltage of a power supply circuit to a start operating part when the start signal is extracted by the extracting means to operate the start operating part. And control means.

[0008] A control method for a center device according to the present invention is a control method for a center device for transmitting an analog television broadcast signal to a terminal device on a plurality of analog channels. It is characterized in that a start signal is superimposed in a transmission band of a television broadcast signal. The control method of the terminal device of the present invention includes:
An analog television broadcast comprising a constant operation section to which the output voltage of the power supply circuit is constantly supplied and a start-up operation section to which the output voltage of the power supply circuit is not supplied when in the standby state, and transmitted from the center device through a plurality of analog channels. A method for controlling a terminal device that receives a signal, comprising: receiving a television broadcast signal from a center device on a predetermined analog channel when the operation unit is in a standby state; and extracting an activation signal from the received television broadcast signal. Then, when the start signal is extracted, the output voltage of the power supply circuit is supplied to the start operation unit to operate the start operation unit.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a CATV according to the present invention.
1 shows a broadcasting system. This CATV broadcasting system includes a center device 1 and a terminal device 2. The terminal device 2 is connected to the television receiver 3. Although a plurality of terminal devices including the terminal device 2 are connected to the center device 1, only the terminal device 2 will be described here. The configuration of a plurality of terminal devices other than the terminal device 2 is the same as the configuration of the terminal device 2 described below.

As shown in FIG. 2, the center device 1 includes a modulator 11 and a set-top box (STB) starting device 1.
2 and a mixer 13. The modulation device 11 includes a plurality of analog modulation units and a plurality of digital modulation units. In this embodiment, one analog modulation section 21 and one digital modulation section 22 are indicated by reference numerals, but both the analog modulation section and the digital modulation section are provided for the number of channels.

An analog modulator 21 has a baseband input terminal IN for analog video and audio signals.
v and INa are provided, and a TV tuner 24 is connected to the input terminals thereof. The TV tuner 24 receives a predetermined television broadcast wave and outputs an analog video signal and an audio signal. Analog modulator 21
Is an AM corresponding to an analog video signal as a modulator.
AM modulator 31 that performs (amplitude) modulation, and FM modulator 3 that performs FM (frequency) modulation according to an analog audio signal
2 is provided. The analog modulation section 21 further includes a local oscillator 33, mixers 34 and 35, and an up-converter 36. The local oscillator 33 generates an oscillation signal of a predetermined frequency, and supplies the oscillation signal to the mixers 34 and 35. The mixer 34 mixes the output signal of the AM modulator 31 and the oscillation signal to generate a video intermediate frequency signal having a center frequency of, for example, 45.75 MHz. Mixer 35
Mixes the output signal of the FM modulator 32 and the oscillation signal to generate an audio intermediate frequency signal having a center frequency of, for example, 41.25 MHz.

The analog modulation section 21 has an output terminal MIFaOUT and an input terminal MIFaIN for an audio intermediate frequency signal. The STB activation device 12 is connected to the output terminal MIFaOUT and the input terminal MIFaIN. The audio intermediate frequency signal from the mixer 35 is supplied to the S terminal via the output terminal MIFaOUT.
It is supplied to the TB activation device 12. An upconverter 36 is connected to the input terminal MIFaIN in the analog modulation section 21. The audio intermediate frequency signal output from the STB activation device 12 is supplied to the up-converter 36 via the input terminal MIFaIN.

The upconverter 36 is also supplied with a video intermediate frequency signal from the mixer 34. The up-converter 36 mixes the video intermediate frequency signal with an oscillation signal output from a local oscillator (not shown), and
a1 (for example, one channel), a video RF signal Fv having a video frequency (for example, 91.25 MHz) is generated, and at the same time, an oscillation signal is mixed with an audio intermediate frequency signal to produce an audio frequency for the analog channel CHa1 (for example, 95. Audio RF with 75 MHz)
A signal Fa is generated. The output video RF signal Fv and audio RF signal Fa of the up-converter 36 are within the bandwidth of one channel of the analog television signal,
These signals are supplied to the mixer 13.

The STB activation device 12 includes an analog modulation unit 2
In addition to the input terminal SIFaIN and the output terminal SIFaOUT corresponding to the one output terminal MIFaOUT and the input terminal MIFaIN, a serial terminal S-PORT for serial connection with the microcomputer 14 in accordance with, for example, the RC-232C standard is provided.
The connection may be made using another terminal such as an Ethernet (registered trademark) terminal.

The STB activation device 12 includes a data converter 41
And an AM multiplex modulator 42. The data converter 41 is connected to the serial terminal S-PO
The data signal (start signal) supplied via the RT is code-converted, for example, from the NRZ format to the BPS format. The AM multiplex modulator 42 receives an input terminal SIFaIN from the analog modulator 21.
The output data signal of the data converter 41 is AM-multiplexed with respect to the audio intermediate frequency signal input through the. A
The audio intermediate frequency signal subjected to AM modulation by the M multiplex modulator 42 is supplied to an output terminal SIFaOUT and returned to an input terminal MIFaIN of the up-converter 36.

The analog video signal and audio signal input to the baseband input terminals INv and INa of the analog modulation section 21 are not limited to the TV tuner 24, but may be analog output from a source such as a tape recorder, a disc player, or a studio. Video signal and audio signal. The digital modulator 22 includes a QAM modulator 38 and an up-converter 39. QAM modulator 3
The BS / CS tuner 25 is connected to the input terminal DIN of the 8. The BS / CS tuner 25 receives a predetermined digital television broadcast wave and outputs an MPEG format data signal. The QAM modulator 38 performs QAM modulation according to an MPEG format data signal (MPEG2 transport stream) and outputs a digital intermediate frequency signal. The up-converter 39 is a QAM modulator 38
Is converted into an RF signal of the frequency of the digital channel CHd1 (for example, 500 MHz) and output to the mixer 13.

Further, the center device 1 is further provided with a control signal modulating section 23 comprising a QAM modulator 26 and an up-converter 27. The QAM modulator 26 performs QAM modulation according to a control signal to perform a so-called OOB (Out Of
Band) to convert the data to an intermediate frequency signal. The up-converter 27 converts the output intermediate frequency signal of the QAM modulator 26 to the frequency of the control channel CHc (for example, 300 MHz).
The signal is converted into an RF signal of z) and output to the mixer 13. The control signal includes distribution information, and also includes viewing control information and digital program guide data such as an EPG (Electronic Program Guide) for each channel.

The mixer 13 mixes the RF signals output from the modulation units including the analog modulation unit 21, the digital modulation unit 22, and the control signal modulation unit 23, and outputs the result as a CATV signal. The CATV signal is supplied to the terminal device 2. Note that a relay device may be inserted between the center device 1 and the terminal device 2. The terminal device 2 includes a constant operation unit (reference numeral 6 in FIG. 4) in which power is always turned on, and a start operation unit (reference numeral 7 in FIG. 4) which starts after the power is turned on in accordance with the operation of the constant operation unit. ).

As shown by a white block in FIG. 3, the constantly operating unit 6 includes a distribution circuit 51, an in-band tuner 52, a video demodulator 53, an AM detection circuit 54, and a sub CPU 55.
It has. The start-up operation section 7 includes an audio demodulator 57, an OOB tuner 58, QAM demodulators 59 and 60, and a DEMUX (Demulx), as indicated by a hunting block in FIG.
a tiplexer) 61, a CPU 62, a UART 63, and an AV switch circuit 64.

A cable input terminal INc is connected to the distribution circuit 51, and C is connected via the cable input terminal INc.
An ATV signal is provided. The distribution circuit 51 supplies the CATV signal to the in-band tuner 52 and the OOB tuner 58 as it is, and separates and supplies the CATV signal to a VTR (video tape recorder) terminal VTROUT and an FM tuner terminal FMOUT.

The in-band tuner 52 is a DEMUX 61
Has a function of selecting a desired reception channel designated by the above, and when the desired reception channel carries an analog television signal, the signal of the frequency of the desired reception channel in the CATV signal is converted to an analog intermediate frequency signal. To the video demodulator 53, and when the receiving channel carries a digital television signal, C
The signal of the frequency of the desired reception channel of the ATV signal is converted into a digital intermediate frequency signal and supplied to the QAM demodulator 60.

The video demodulator 53 demodulates the analog intermediate frequency signal and outputs an analog video signal. The video demodulator 53 supplies an audio component in the analog intermediate frequency signal to the AM detection circuit 54 and the audio demodulator 57. The AM detection circuit 54 performs AM detection on the audio component in the analog intermediate frequency signal, and supplies the detection result to the sub CPU 55. The audio demodulator 57 FM-demodulates an audio component in the analog intermediate frequency signal and outputs a baseband audio signal. The analog video signal output from the video demodulator 53 and the analog audio signal output from the audio demodulator 57 are supplied to the DEMUX 61.

The QAM demodulator 60 is provided for the in-band tuner 5.
The digital intermediate frequency signal output from
M demodulation to obtain an MPEG format data signal (MPEG2 transport stream), which is DEMUX61
To supply. The OOB tuner 58 converts a signal of the frequency of the control channel CHc of the CATV signal into an intermediate frequency signal for a control signal, and supplies the intermediate frequency signal to the QAM demodulator 59. The QAM demodulator 59 obtains a control signal by performing QAM demodulation on the intermediate frequency signal for the control signal,
Feed to 1.

The DEMUX 61 has an MPEG decoder and a control CPU (both not shown) therein, and includes a ten key 76b and a channel up / down key 76c of an operation unit 76 described later or a ten key 78b and a channel up of a remote control transmitter 78. A desired reception channel is set according to the operation of the down key 78c. Data indicating the desired reception channel is supplied to the in-band tuner 52.

The DEMUX 61 has a QAM demodulator 6
MPEG data signal supplied from MPEG0
Demodulated by a decoder to generate a digital video signal and a digital audio signal. Also, DEMUX
The A / D converter 61 converts the analog video signal output from the video demodulator 53 and the analog audio signal output from the audio demodulator 57 into a digital video signal and a digital audio signal.

Further, the DEMUX 61 generates an analog video signal and an audio signal by performing D / A conversion of the digital video signal and the digital audio signal.
In addition, a component signal for Hi-Vision including a luminance signal and a color difference signal is generated. The various signals described above obtained by the DEMUX 61 are supplied to the output terminal of the terminal device 2. Digital audio output terminal OUTD
A, D4 video output terminal OUTDV, component output terminal OU
TCOMP (Y, PB, PR), VTR recording output terminal VTR REC (V, R,
L), TV signal S output terminal OUTS, TV output terminal OUTTV (V, R,
L), and a VTR input terminal INVTR (V, R, L). A digital audio signal is supplied to the digital audio output terminal OUTDA, and a digital video signal is supplied to the D4 video output terminal OUTDV. Signal supply to the digital audio output terminal OUTDA and the D4 video output terminal OUTDV is performed according to the operation state of the D terminal switch 70.

Component output terminal OUTCOMP (Y, PB, PR)
Is supplied with a component signal for high definition. Y is a luminance signal, and PB and PR are color difference signals. D / A converted analog video signals and audio signals are supplied to the VTR recording output terminal VTR REC (V, R, L). V
Is a video signal, R is a right channel audio signal, and L is a left channel audio signal. Analog video signals and audio signals are supplied from the AV switch circuit 64 to the TV signal S output terminal OUTS and the TV output terminal OUTTV (V, R, L). The AV switch circuit 64 is a DEMUX61
Analog video and audio signals from VT
One of the analog video signal and the audio signal input to the R input terminal VTRIN (V, R, L) is selectively selected according to the operation according to the operation of the TV signal S output terminal OUTS and TV output terminal OU.
Supply to TTV (V, R, L).

The CPU 62 generates a signal for controlling the video tape recorder in accordance with the generation of the video signal and the audio signal in the DEMUX 61 and supplies the signal to the VTR controller terminal VTRCONT. The UART 63 is provided between the serial terminal SERIAL and the DEMUX 61, and controls signal input / output with peripheral devices such as a modem connected to the serial terminal SERIAL.

If the television receiver 3 has a digital input terminal, it is connected to the digital audio output terminal OUTDA and the D4 video output terminal OUTDV of the terminal device 2. Also,
When the analog input terminal of the television receiver 3 is used, the TV signal S output terminal OUTS and the TV output terminal OUTTV
One of (V, R, L) is used for connection. FIG. 4 shows a power supply control unit that supplies power to the above-mentioned constant operation unit 6 and activation operation unit 7 of the terminal device shown in FIG. In the power control unit, signals obtained in the sub CPU 55 and the DEMUX 61 are used. The power supply control unit has a power supply circuit 71. The power supply circuit 71 has a commercial power supply AC1.
00V is supplied via the main switch 72. An outlet 74 is connected between the power supply circuit 71 and the main switch 72 via a switch 73. The AC plug 3a of the television receiver 3 is inserted into the outlet 74.
The switch 73 is on / off controlled in accordance with a signal output from the DEMUX 61.

The power supply circuit 71 outputs a predetermined voltage to the output terminal OUT when the main switch 72 is turned on. Its output terminal OUT
Is always connected to the operating unit 6 directly, and the starting operating unit 7 is connected via the switch 75. Switch 75
Are turned on / off in accordance with a signal output from the sub CPU 55. An operation unit 76 and a light receiving unit 77 are connected to the sub CPU 55. The operation unit 76 includes a power key 76a,
Numeric keypad 76b and channel up / down key 76c
In addition, a standby display LED 76d is provided. The light receiving section 77 receives a remote control signal transmitted from the remote control transmitter 78 as infrared rays. The remote control transmitter 78 includes a power key 78a, a numeric keypad 78b, and a channel up / down key 78c, and transmits a remote control signal corresponding to the operation from a light emitting unit (not shown).

In the CATV broadcasting system having such a configuration, the terminal device 2 can enter a standby state according to the operation of the operation unit 76 or the remote control transmitter 78. In the standby state, the power supply to the activation operation unit 7 of the terminal device 2 is stopped, and the power of the television receiver 3 connected to the terminal device 2 as described above is turned off. In this standby state, power is supplied to the constantly operating unit 6 of the terminal device 2, so that a predetermined analog channel (the analog channel CHa1 in this embodiment) of the supplied CATV signal is monitored. The standby state can be automatically canceled by obtaining the data signal emitted from the microcomputer 14.

The data signal has a data structure as shown in FIG. That is, the data signal is represented by a 16-bit start flag (0000, 0000, 0000, 00
01), an address for designating the terminal device, command data indicating the contents of the instruction, an exclusive OR of the address and the command data, a 10-bit BCC that is the complement of "1", and a stop flag of more than 10 bits (0000 , 0000,00)
It consists of valid data consisting of When the data signal is transmitted, as shown in FIG. 6, the valid data of FIG. 5 is repeated three times, and before and after that, 16-bit "1" is transmitted.
Is added.

Command data consists of 10 bits.
As shown in FIG. 7, an 8-bit command data body,
It consists of bit parity and 1-bit isolation. As the command data body, for example, a bit sequence (1000,0000) for instructing the start operation unit 7 of the terminal device 2 to start operation and a bit sequence (0000,0000) for instructing stop of the operation of the start operation unit 7 of the terminal device 2 There is.

The address has three modes: all terminal device designation, specific terminal device designation, and group designation. In the case of all terminal device designations, as shown in FIG. 8, the address is represented by 8-bit mode data (1111, 1110) indicating all terminal device designations, 1-bit parity, and 1-bit isolation. Be composed. In the case of a specific terminal device designation, as shown in FIG. 9, the address is 8-bit mode data (0000,11) indicating the specific terminal device designation.
11) Following 1-bit parity P and 1-bit isolation I, address data for designating a 32-bit terminal device, 1-bit parity P, and 1-bit isolation I four times It is a repeating structure. In the case of group designation, the address is 8-bit mode data indicating the group designation as shown in FIG.
(0000,0000 to 0000,1110) Following the 1-bit parity P and the 1-bit isolation I, an 8-bit sub-flag for distinguishing between notification and control is provided. The notification indicates transmission of information that needs to be notified to the user of the terminal device, and the control indicates control in the terminal device. Code is 1000,0000 for announcement, 0100,00 for control
00. After the sub-flag, a 1-bit parity P,
Then, 1-bit isolation I follows, followed by group data, 1-bit parity P, and 1-bit isolation I. The group data is data for specifying a group divided in advance for each terminal device, and is represented by 8 bits. As shown in FIG. 10, up to 256 groups can be shown by repeating group data, 1-bit parity P, and 1-bit isolation I.

In order for the terminal device 2 to enter the standby state, it is necessary to perform a normal reception operation (ie, the switches 72, 73, 75).
(When is turned on), the standby shift operation needs to be performed. Next, the standby shift operation will be described. As shown in FIG. 11, the sub CPU 55 of the terminal device 2 determines whether the power key 76a of the operation unit 76 or the power key 78a of the remote control transmitter 78 has been operated (Step S).
1). When the power key 76a of the operation unit 76 or the power key 78a of the remote control transmitter 78 is operated, a command to switch the channel to the analog channel CHa1 is issued (step S2). The channel switching command is supplied to the DEMUX 61, and the receiving channel of the in-band tuner 52 is switched to the analog channel CHa1 by a CPU (not shown) in the DEMUX 61. After the generation of the channel switching command, the sub CPU 55 stops the power supply to the activation operation unit 7 (Step S3). Step S3
When the power supply is stopped, first, the sub CPU 55
A standby command is issued to the MUX 61, and the CPU in the DEMUX 61 turns off the switch 73 in response to the standby command. When the switch 73 is turned off, the supply of 100 V commercial power to the television receiver 3 is cut off, so that all operations of the television receiver 3 are stopped.
Next, the sub CPU 55 turns off the switch 75.
When the switch 75 is turned off, the power supply from the power supply circuit 71 to the start-up operation unit 7 including the DEMUX 61 is stopped.

After stopping the power supply to the start-up operation section 7 in step S3, the sub CPU 55 turns on the standby display LED 76d of the operation section 76 (step S4).
And it will be in a standby state. The standby release operation for releasing the standby state when the terminal device 2 is in the standby state will be described below.

A data signal is generated in response to a keyboard operation by the operator of the personal computer 14, and is supplied from the personal computer 14 to the STB activation device 12. Although the data signal will be described later, it is assumed that the data signal issued here indicates a command to activate the terminal device 2. In the STB activation device 12, the supplied data signal is code-converted by the data converter 41,
The signal is supplied to the AM multiplex modulator 42. AM multiplex modulator 42
From the analog modulation unit 21 via the input terminal SIFaIN.
An audio intermediate frequency signal subjected to M modulation is input, and the AM multiplex modulator 42 multiplexes the output data signal of the data converter 41 with the audio intermediate frequency signal. This AM multiplexing is performed, for example, at 41.25 MHz.
Is a signal waveform in which an AM component corresponding to the data signal is superimposed on an audio intermediate frequency signal component having a center frequency of. The center frequency of the AM component is equal to the center frequency of the audio intermediate frequency signal component.

The audio intermediate frequency signal that has been subjected to AM multiplexing returns to the analog modulation section 21 and
6 is converted into an audio RF signal Fa having the audio frequency of the analog channel CHa1. The up-converter 36 generates a video RF signal Fv of the video frequency of the analog channel CHa1 together with the audio RF signal Fa. Analog channel CHa
In a band of 1 (for example, 6 MHz), as shown in FIG.
The M component is superimposed.

The video RF signal Fv and audio RF signal Fa of the analog channel CHa1 are
Is mixed with other RF signals at
It is output to the terminal device 2 as an ATV signal. Terminal device 2
Since the power supply voltage is supplied from the power supply circuit 17 to the constantly operating unit 6 even during the standby state, it is possible to receive the RF signal of the analog channel CHa1, which is a specific channel of the supplied CATV signal. it can. That is, the CATV signal is supplied to the in-band tuner 52 via the distribution circuit 51. In step S2, the reception channel of the in-band tuner 52 has been switched to the analog channel CHa1, so that the video RF signal Fv and the audio RF signal Fa, which are RF signals in the frequency band of the analog channel CHa1, are output by the in-band tuner 52. Received. Video RF
The video demodulator 53 to which the signal Fv and the audio RF signal Fa are supplied generates a baseband video signal from the video RF signal Fv, but the video signal is output from the terminal device 2 because the DEMUX 61 is not operating. There is no. The audio RF signal Fa is supplied from the video demodulator 53 to the AM detection circuit 54. The AM detection circuit 54 performs AM detection on the audio RF signal Fa to perform audio RF
The data signal component included in the signal Fa is output to the sub CPU 55.

When the data signal component is supplied from the AM detection circuit 54, the sub CPU 55, as shown in FIG.
The data signal component is decoded (decoded) to obtain an original data signal (step S11), and it is determined from the content of the data signal whether or not the command is addressed to itself (that is, addressed to the terminal device 2) (step S11). Step S12). This is determined from the mode data described above. If the command is not addressed to itself, the command is ignored. On the other hand, if the command is addressed to itself, a switch-on command is issued to the switch 75 (step S13). Thus, the switch 75 is turned on, and the power supply circuit 71 is
Supplies a power supply voltage. Therefore, the activation operation unit 7 starts operating.

After execution of step S13, the sub CPU 55 transmits the contents of the command addressed to itself to the DEMUX 61, requests the DEMUX 61 to perform an operation according to the contents of the command (step S14), and displays the standby display LED 76d of the operation unit 76 Is stopped (step S1).
5). Thus, the standby state of the terminal device 2 has been released.

The CPU of the DEMUX 61 executes step S1.
The control operation corresponding to the operation request of No. 4 is started. If the content of the command is for notification, the switch 73 is turned on and the power of the television receiver 3 is turned on. For example, the notification content is displayed on the television receiver 3 by the above-described EPG, Displaying a notification channel is performed. It is also possible to notify the user of the terminal device of the announcement broadcast by a flicker or a buzzer (neither is shown). In the case of control, for example, collection of viewing information stored in a memory (not shown) in the DEMUX 61 of the terminal device 2, update of a reception contract content, and control of download of necessary software are performed.

When the terminal device 2 receives the EPG data, the OOB tuner 58 is used. The OOB tuner 58 converts a signal of the frequency of the control channel CHc in the CATV signal supplied from the center device 1 into an intermediate frequency signal for a control signal, and supplies the intermediate frequency signal to the QAM demodulator 59. The QAM demodulator 59 performs QAM demodulation on the intermediate frequency signal for the control signal to obtain a control signal, that is, EPG data, and supplies it to the DEMUX 61. DEMUX
Numeral 61 stores EPG data in the above-mentioned memory for each channel, and supplies it as an image signal to an output terminal such as a D4 image output terminal OUTDV in accordance with an operation of the operation unit 76 or the remote control transmitter 78 or a command of a data signal.

In the embodiment described above, the AM multiplex modulator 42 for AM multiplexing the output data signal of the data converter 41 with the audio intermediate frequency signal input from the analog modulator 21 via the input terminal SIFaIN is provided. Although provided, an FM modulator that performs FM modulation according to the output data signal of the data converter 41 may be used instead of the AM multiplex modulator 42. For example, as shown in FIG.
The TB activation device 12 includes a data converter 41 and an FM modulator 43. The FM modulator 42 FM-modulates the carrier signal Fd of a predetermined frequency in accordance with the output data signal of the data converter 41, together with the audio intermediate frequency signal input from the AM multiplexing analog modulator 21 via the input terminal SIFaIN. The signal is supplied to the input terminal MIFaIN of the up-converter 36 via the output terminal SIFaOUT. In this FM modulation, for example, an FM component corresponding to a data signal is located around a frequency 0.25 MHz higher than an audio intermediate frequency signal component having a center frequency of 41.25 MHz.
That is, in the band of the analog channel CHa1 (for example, 6 MHz), as shown in FIG. 15, an FM component that carries a data signal at a frequency slightly higher than the audio RF signal Fa is arranged.

In contrast to the center device 1 provided with the FM modulator 43, in the terminal device 2, an FM detection circuit 65 is provided in place of the AM detection circuit 54 as shown in FIG. The FM detection circuit 65 performs FM detection of a predetermined frequency component in the analog intermediate frequency signal, and supplies a result of the detection, that is, a data signal component to the sub CPU 55. The other configuration of the terminal device is the same as that of the terminal device 2 shown in FIG.

Although the above embodiment is a CATV broadcasting system to which the present invention is applied, the present invention can be applied to a satellite broadcasting system.

[0047]

As described above, according to the present invention, in the standby state, the power supply of the start-up operation unit, which consumes more power than the operation unit at all times, is stopped, so that the power consumption of the terminal device is sufficiently reduced. be able to. In the standby state, the terminal device can be activated so that irregular distribution information sent from the center device can be received by the operation of the constantly operating unit.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a CATV broadcasting system according to the present invention.

FIG. 2 is a block diagram showing a configuration of a center device in the system of FIG.

FIG. 3 is a block diagram showing a configuration of a terminal device in the system of FIG. 1;

FIG. 4 is a block diagram illustrating a configuration of a power control unit of the terminal device in the system of FIG. 1;

FIG. 5 is a diagram showing a data structure of a data signal.

FIG. 6 is a diagram showing a data structure of actual transmission data.

FIG. 7 is a diagram showing a data structure of command data.

FIG. 8 is a diagram showing a data structure of all terminal device-specified addresses.

FIG. 9 is a diagram showing a data structure of an address specified by a specific terminal device.

FIG. 10 is a diagram showing a data structure of an address designated by a group.

FIG. 11 is a flowchart illustrating an operation when the terminal device shifts to a standby state.

12 is a diagram showing a signal distribution in a band of an analog channel CHa1 output from the center device of FIG. 2;

FIG. 13 is a flowchart illustrating an operation when the terminal device starts up from a standby state.

FIG. 14 is a block diagram showing a configuration of a center device in a system according to another embodiment of the present invention.

FIG. 15 is a diagram showing a signal distribution in a band of an analog channel CHa1 output from the center device of FIG. 14;

FIG. 16 is a block diagram showing a configuration of a terminal device in a system according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Center apparatus 2 Terminal apparatus 3 Television receiver 6 Constant operation part 7 Start-up operation part 11 Modulator 12 STB starter 13 Mixer 52 In-band tuner 54 AM detection circuit 55 Sub CPU 61 DEMUX 65 FM detection circuit

Continued on the front page F term (reference) 5C063 AB01 AB06 AB15 AC01 AC06 CA36 DA07 5C064 BA02 BB03 BC16 BC20 BD08 BD09 BD14

Claims (12)

[Claims] 1. A broadcasting system for transmitting an analog television broadcast signal from a center device to a terminal device through a plurality of analog channels, wherein the center device broadcasts a predetermined analog channel of the plurality of analog channels. The terminal device includes a superimposing unit that superimposes an activation signal within a signal transmission band, wherein the terminal device is configured to constantly supply an output voltage of a power supply circuit, and to supply an output voltage of the power supply circuit when in a standby state. A first operation unit that receives a television broadcast signal from the center device on the predetermined analog channel when in a standby state; and a first operation unit that receives a television broadcast signal from the center device when in a standby state. Extracting means for extracting the activation signal from the extracted television broadcast signal; and the extraction means extracts the activation signal. Broadcasting system characterized by having a control means for operating the start operation unit an output voltage of the power supply circuit is supplied to the activation operation part to come. 2. The control device according to claim 1, wherein the activation operation unit receives distribution information transmitted from the center device on a control channel different from the plurality of analog channels, and the plurality of analog channels from the center device. Is a third receiving means for receiving a digital broadcast signal transmitted on a different digital channel, and the distribution information or third information received by the second receiving means.
2. A broadcasting system according to claim 1, further comprising a processing unit for demodulating a digital broadcast signal received by the receiving unit. 3. The superimposing means superimposes a start signal by amplitude modulation on an audio component of the television broadcast signal within a transmission band of the television broadcast signal, and the extracting means comprises: 2. The broadcast system according to claim 1, wherein amplitude detection is performed on an audio component of the received television broadcast signal. 4. The superimposing means superimposes a start signal on the television broadcast signal by frequency modulation within a transmission band of the television broadcast signal, and the extracting means receives the start signal by the first receiving means. The broadcast system according to claim 1, wherein frequency detection is performed on the television broadcast signal. 5. The control unit supplies the output voltage of the power supply circuit to the start-up operation unit when the start-up signal extracted by the extraction unit indicates a predetermined address to operate the start-up operation unit. The broadcasting system according to claim 1, wherein: 6. The power supply according to claim 1, wherein the power consumption of the constant operation unit is smaller than the power consumption of the activation operation unit.
Broadcast system as described. 7. The broadcasting system according to claim 1, wherein the control unit turns on the power of the television receiver when the start signal is extracted by the extraction unit. 8. The broadcasting system according to claim 1, wherein said receiving means is switched to a receiving state of said predetermined channel immediately before shifting to a standby state. 9. A center device for transmitting an analog television broadcast signal to a terminal device through a plurality of analog channels, wherein the start signal is set within a transmission band of a television broadcast signal of a predetermined analog channel among the plurality of analog channels. A center device having a superimposing means for superimposing the superimposition. 10. A terminal device for receiving an analog television broadcast signal transmitted on a plurality of analog channels from a center device, comprising: a constantly operating unit to which an output voltage of a power supply circuit is constantly supplied; A starting operation unit to which the output voltage of the power supply circuit is not supplied, wherein the constant operation unit receives a television broadcast signal from the center device on the predetermined analog channel when in a standby state; Extracting means for extracting a start signal from a television broadcast signal received by the first receiving means; and supplying the output voltage of the power supply circuit to the start operation unit when the start signal is extracted by the extract means. And a control unit for operating the activation operation unit. 11. A control method for a center device for transmitting an analog television broadcast signal to a terminal device through a plurality of analog channels, the control method comprising: transmitting a television broadcast signal of a predetermined analog channel among the plurality of analog channels; A control method for a center device, comprising: superimposing a start signal on a center device. 12. A power supply circuit comprising an always-on operation unit to which an output voltage is always supplied, and a standby operation unit to which an output voltage of the power supply circuit is not supplied when in a standby state. A method of controlling a terminal device that receives a transmitted analog television broadcast signal, comprising: receiving a television broadcast signal from the center device on the predetermined analog channel when the constant operation unit is in a standby state; A control method, comprising: extracting the start signal from the television broadcast signal thus obtained; and supplying the output voltage of the power supply circuit to the start operation unit to operate the start operation unit when the start signal is extracted.