JP2007306099A - Television receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a television receiver which suppressing power consumption by shortening a time between channel selection and reproduction of a received signal. <P>SOLUTION: The television receiver has a configuration provided with: two or more demodulation circuits; output control circuits existing corresponding to each of the demodulation circuits, and transmitting or interrupting a transport stream output of a corresponding demodulation circuit on the basis of a control signal; a decoding circuit performing a decoding operation on the basis of the output of the output control circuit only when the output of the output control circuit has an amplitude variation, and the output is a signal having rise or fall not less than a threshold; and a controller for transmitting a control signal for allowing the output to pass to the output control signal corresponding to the signal-receiving demodulation circuit, and transmitting a control signal for interrupting the output to the output control circuit corresponding to the demodulation circuit having no necessary of reception. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a television receiver having low power consumption and high speed in time from channel selection to reproduction.

  In many cases, television receivers are equipped with two or more tuners in order to support a plurality of broadcasts. A conventional television receiving apparatus identifies whether or not to reproduce any of the signals selected and received by a plurality of tuners, and selects and receives a signal that is not reproduced based on the identification result. The power supply to the tuner is stopped (for example, refer to Patent Document 1).

In the method of Patent Document 1, it takes time from channel selection to reproduction in digital broadcasting. For this reason, a plurality of tuners or demodulation circuits have been operated without using the control method as in Patent Document 1.
JP-A-10-108115

  However, in the above-described conventional configuration, the power supply to the tuner that selects and receives a signal that is not reproduced is stopped. Therefore, when reproduction is performed using a tuner that has stopped the power supply, the power supply is stopped. Compared to a television receiver that does not perform the above, there is a problem that it takes time to restore the power supply and reproduce the signal received from the channel selection. This is because, particularly in digital broadcasting, it takes time to set the demodulation circuit and the transport stream that is the output after passing through the demodulation circuit and the error correction circuit.

  In addition, since digital broadcasting needs to decode a transport stream into video output and audio output, it has a problem that it takes time to output an image compared to analog broadcasting that does not need to.

  Therefore, in order to perform decoding at high speed, the operation is continued so that the input of the decoding circuit can be received, and the operation is performed so that the transport stream is waited for input and can be decoded as soon as it is input. Here, the operation of the decoding circuit will be described. The amplitude of the signal input to the decoding circuit is observed, and when the rising or falling of the signal equal to or higher than the threshold is observed, it is determined that the signal is input, and the decoding circuit starts the decoding operation. Therefore, even if a signal that cannot be decoded is detected, the decoding circuit operates but does not output an image when there is fluctuation in amplitude at the input of the decoding circuit and a rise or fall is observed. In order to do so, there is a problem that power consumption becomes high.

  For this reason, there is a problem in that the signal amplitudes and the decoding circuit operates and the power consumption increases during the timing when the plurality of tuner operations are switched and until the demodulation circuit is synchronized.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a television receiver capable of shortening the time required to reproduce a signal received from a channel selection and suppressing power consumption. .

  In order to achieve this object, the television receiver of the present invention exists corresponding to each of the two or more demodulation circuits and each of the demodulation circuits, and the transport stream output of the corresponding demodulation circuit is based on the control signal. An output control circuit that passes or blocks, and a decode circuit that performs a decoding operation based on the output of the output control circuit only when the output of the output control circuit is a signal having an amplitude variation and having a rising or falling higher than a threshold value And a control signal for transmitting to the output control circuit corresponding to the demodulation circuit to be received and for blocking the output control circuit corresponding to the demodulation circuit that does not require reception. And a control device that transmits a signal.

  Also, passing in the output control circuit is by making the transport stream output of the demodulator circuit the output of the output control circuit, and blocking is to connect the output of the output control circuit to a fixed voltage, ground, or high It has a configuration realized by using impedance.

  Further, the output control circuit is operated by a register or formed on a demodulating digital LSI.

  The demodulator circuit includes an OFDM demodulator circuit for terrestrial digital broadcast, a PSK demodulator circuit for satellite digital broadcast, or a QAM demodulator circuit for CATV digital broadcast.

  As described above, the present invention provides an excellent effect of shortening the time until the signal received from the channel selection is reproduced and suppressing power consumption.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing the configuration of the television receiver according to Embodiment 1 of the present invention. It is explanatory drawing which has the apparatus which outputs a digital broadcast, after selecting the channel and demodulating the signal received from the tuner, and controlling the transport stream input into a decoder circuit. In the television receiver 117, the terrestrial digital broadcast antenna 101 is a digital terrestrial broadcast antenna used for receiving terrestrial digital broadcast. The RF (Radio Frequency) signal output from the terrestrial digital broadcast antenna 101 selects a channel using the terrestrial digital broadcast tuner 103 and converts it to an intermediate frequency signal. An AD (Analog Digital) converter 105 converts the intermediate frequency signal into terrestrial digital data. Terrestrial digital data is input to an OFDM (Orthogonal Frequency Division Multiplexing) demodulating circuit 107 to perform a demodulation operation. The error correction circuit 109 performs error correction on the demodulated signal to form a transport stream. The output control circuit 111 controls the output of the transport stream of the received terrestrial digital broadcast.

  The satellite digital broadcast antenna 102 is an antenna for satellite broadcast used for receiving satellite digital broadcast. The satellite digital broadcast tuner 104 converts an IF (Intermediate Frequency) signal output from the satellite digital broadcast antenna 102 into an IQ (Inphase Quadrature) signal. The AD converter 106 converts the IQ signal into satellite digital data. The satellite digital data is input to a PSK (Phase Shift Keying) demodulation circuit 108 to perform a demodulation operation. The error correction circuit 110 performs error correction on the satellite digital signal on which the demodulation operation has been performed, and forms a transport stream. The output control circuit 112 performs control to output a satellite digital broadcast transport stream.

  A TS (Transport Stream) decoder 114 decodes a satellite digital broadcast transport stream and a terrestrial digital broadcast transport stream and outputs the decoded data as video data 115 and audio data 116. The control device 113 controls the transport stream to be decoded by the TS decoder 114 and the output control circuit 111 and the output control circuit 112 in accordance therewith.

  FIG. 2 is a block diagram showing the configuration of the output control circuit according to Embodiment 1 of the present invention. Inside the output control circuits 111 and 112, there are four states by switching the switches. This switching is controlled by an input to the control terminal 206.

  The TS input 201 is connected to an external transport stream. When the TS input 201 and the TS output 205 are connected by a switch, the output control circuits 111 and 112 can output the input transport stream. This state is regarded as a valid state. Since the transport stream is input from the TS output 205 to the TS decoder 114, and the amplitude of the signal fluctuates in the TS decoder 114 and the rise or fall can be observed, the TS decoder 114 detects the input of the signal and starts the decoding operation. Power consumption.

  When the power source 202 and the TS output 205 are connected by a switch, the TS output 205 can output a certain voltage value. When the terminal 203 and the TS output 205 are connected by a switch, the TS output 205 becomes high impedance. When the ground terminal 204 and the TS output 205 are connected by the switch, the ground terminal 204 is grounded, so the TS output 205 becomes 0 volts. In these three states, the transport stream is not output and becomes invalid. Since the amplitude of the input of the TS decoder 114 is fixed, no rise or fall is observed. For this reason, the TS decoder 114 determines that no transport stream is input. As a result, no decoding operation is performed and no power is consumed.

  According to the television receiver of the present invention, when a signal that is not reproduced is selected and reproduced from the tuner that has been received, the time for resetting the demodulator circuit setting and the tuner setting is shortened, and the signal is reproduced until reproduction. Time can be shortened. By stopping the output of signals not related to image output in two or more tuners, the output circuit of the transport stream is stopped, and fluctuations in the amplitude of the signal input to the decoding circuit are eliminated, and the input of the decoding circuit Since the rising or falling of the amplitude cannot be observed in the part, the decoding operation is not performed. Therefore, since the decoding circuit does not operate, power consumption of the circuit can be suppressed.

In this embodiment, the output control circuit 111 and the output control circuit 112 are provided as output control means. However, a terrestrial or satellite digital broadcast demodulation LSI (Large Scale Integration) integrated with an AD converter, a demodulation circuit, and an error correction circuit. It may be embedded in Further, the control method does not use a control device, and a control device may be incorporated in the terrestrial or satellite digital broadcast demodulation LSI and operated by a register of the terrestrial or satellite digital broadcast demodulation LSI.
(Embodiment 2)
FIG. 3 is a block diagram showing the configuration of the television receiver according to Embodiment 2 of the present invention, and is an explanatory diagram for receiving terrestrial digital broadcast and CATV (Cable Television) digital broadcast. In FIG. 3, the same components as those in FIG. In FIG. 3, a CATV digital broadcast input from the input / output terminal 301 is selected using a CATV digital broadcast tuner 302 and converted into an intermediate frequency signal. The AD converter 303 converts the intermediate frequency signal into CATV digital data. The CATV digital data is input to a QAM (Quadrature Amplitude Modulation) demodulation circuit 304 to perform a demodulation operation. Thereafter, the operation is the same as after the demodulating operation of the satellite digital broadcasting.

  In this embodiment, the digital terrestrial broadcast tuner 103 and the AD converter 105 for receiving the terrestrial digital broadcast, and the CATV digital broadcast tuner 302 and the AD converter 303 for receiving the CATV digital broadcast are provided in each demodulator. It may be common for broadcasting.

  In Embodiment 2, the output control circuit may be combined with a television receiver in which two or more demodulation circuits are combined instead of the OFDM demodulation circuit and the PSK demodulation circuit or the OFDM demodulation circuit and the QAM demodulation circuit.

  The television receiver according to the present invention can shorten the time until playback from the selected tuner, and thus is useful in terms of low power consumption and high speed of time from channel selection to playback.

1 is a block diagram showing a configuration of a television receiver according to Embodiment 1 of the present invention. The block diagram which shows the structure of the output control circuit in Embodiment 1 of this invention. The block diagram which shows the structure of the television receiver in Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Terrestrial digital broadcasting antenna 102 Satellite digital broadcasting antenna 103 Terrestrial digital broadcasting tuner 104 Satellite digital broadcasting tuner 105,106,303 AD converter 107 OFDM demodulation circuit 108 PSK demodulation circuit 109 Error correction circuit 110 Error correction circuit 111 Output control circuit 112 Output control Circuit 113 Controller 114 TS decoder 115 Video data 116 Audio data 117 Television receiver 201 TS input 202 Fixed voltage power supply 203 Terminal 204 Ground terminal 205 Output terminal 206 Control terminal 301 Input / output terminal 302 CATV digital broadcast tuner 303 AD converter 304 QAM Demodulator circuit

Claims (4)

Two or more demodulation circuits;
An output control circuit that exists corresponding to each of the demodulation circuits, and passes or blocks a transport stream output of the corresponding demodulation circuit based on a control signal;
A decoding circuit that performs a decoding operation based on the output of the output control circuit only when the output of the output control circuit is a signal having an amplitude variation and having a rising or falling edge equal to or higher than a threshold;
A control signal for transmitting to the output control circuit corresponding to the demodulation circuit to be received is transmitted and a control signal for blocking the output control circuit corresponding to the demodulation circuit that does not need to be received. A control device to transmit;
A television receiver. Passing in the output control circuit makes the transport stream output of the demodulator circuit the output of the output control circuit, and shutting off connects the output of the output control circuit to a fixed voltage, grounds, or goes to high impedance The television receiver according to claim 1, which is realized by: The television receiver according to claim 2, wherein the output control circuit is operated by a register or formed on a demodulating digital LSI. 2. The television receiver according to claim 1, wherein the demodulation circuit includes any of an OFDM demodulation circuit in terrestrial digital broadcasting, a PSK demodulation circuit in satellite digital broadcasting, or a QAM demodulation circuit in CATV digital broadcasting.

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