JPH0646380A - Transmission signal receiver - Google Patents

Abstract

PURPOSE:To improve the operability of an user by simple constitution by outputting digital video and/or audio signals obtained by A/D converting reception signals and then decoding them while muting them during a reproducing starting period. CONSTITUTION:A digital signal S2 obtained by converting the reception signal S1 at an A/D converter 13 is decoded corresponding to a fixed format by main signal and audio processing circuits 15A and 4. The decoded digital video and/or audio signals DY, DPB, DPR and/or DAD are outputted as analog video and/or audio signals SY, SPB, SPR and SAD through a muting circuit 16 by D/A converters 5A-5C. At this time, during the reproducing starting period from the point of time when the signal S1 is started to be received to the time when a clock synchronized with the signal S2 is reproduced, the circuit 16 is operated and the signals DY, DPB, DPR and/or DAD are muted. Thus, the operability of the user can be improved by the simple constitution.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Field of Industrial Application Conventional Technology Problem to be Solved by the Invention (FIG. 3) Means for Solving the Problem (FIGS. 1 and 2) Action (FIGS. 1 and 2) Example (FIGS. 1 and 2) The invention's effect

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission signal receiving device, and can be applied to, for example, a device for receiving high-definition television signals which are band-compressed and analog-transmitted.

[0003]

2. Description of the Related Art Conventionally, as a satellite television broadcasting using a broadcasting satellite, a high-definition television signal is transmitted by MUSE (mu
ltiple sub-nyquist sampling encoding) There is one that was designed to be band-compressed by analog transmission. Also, in case of satellite television broadcasting, it is not limited to the MUSE system,
A so-called dispersal signal consisting of a triangular wave that is an integral multiple of the frame period is superimposed for energy diffusion, and then frequency-modulated and transmitted, which causes the generation of harmful radio waves by emphasizing only the carrier component when there is no signal. It is designed to prevent this.

Therefore, in the television signal receiving apparatus for receiving the satellite television broadcasting of the MUSE system, after FM demodulating the television broadcasting selected by the tuner, the MUSE signal consisting of the base band component is passed through the low pass filter. The analog signal is extracted, converted into a digital signal by the analog-digital conversion circuit, and input to the MUSE decoder. The dispersal signal component superimposed on the transmitting side is removed by the clamp circuit of the analog-digital conversion circuit.

[0005]

By the way, in the television signal receiving apparatus having such a configuration, as shown in FIG. 3, the MUSE signal S demodulated by FM in the MUSE processing apparatus 1 is used.
Reference numeral 1 denotes a MUSE decoder 3 as a digital signal through a MUSE preprocessing circuit 2 including an analog-digital conversion circuit.
And is input to the voice processing circuit 4 and decoded.

[0006] The results MUSE decoder 3 digital luminance signal DY and the digital color difference signals DP _B made of, for example, each 10 bits, and generates the DP _R, which is converted into an analog signal by a digital-analog converter circuit 5A-5C, the luminance signal SY And color difference signals SP _B and SP _R. Further, the audio processing circuit 4 generates a digital audio signal DAD having, for example, 15 to 16 bits, which is converted into an analog signal by the digital-analog conversion circuit 5D, and the audio signal S
Sent as AD.

However, the MUSE processing apparatus 1 having such a configuration
In order to synchronize the clock in the MUSE decoder 3 with the MUSE signal S1 being received immediately after the power is turned on or the channel is selected, for example, it takes about 1 to 2 seconds.
During this period, there is a problem that the luminance signal SY, the color difference signals SP _B and SP _R, and the audio signal SAD that have not been properly decoded are transmitted, which is still insufficient in terms of usability for the user.

The present invention has been made in consideration of the above points, and it is possible to improve the usability of a user by muting a video signal and / or an audio signal for a predetermined period from the start of receiving a transmission signal with a simple structure. It is intended to propose a signal receiving device.

[0009]

In order to solve the above problems, the present invention provides a transmission signal receiving apparatus 10 for receiving a transmission signal in which a video signal and / or an audio signal is encoded in a predetermined format and analog-transmitted. the received signal S1 obtained by receiving a transmission signal by analog-to-digital conversion with obtaining a digital reception signal S2, the digital video signal DY by decoding in accordance with the digital reception signal S2 to a predetermined the format, DP _B, DP _R and or Reception signal decoding means 15A for transmitting the digital audio signal DAD,
Digital video signals DY, DP _B , D at a predetermined timing
And Miyuto means 16 for Miyuto the P _R and or digital audio signal DAD, converts the digital image signal DY obtained through that Miyuto means 16, DP _B, DP _R and or digital audio signal DAD to an analog signal, the video signal SY , SP _B , SP _R and / or the digital-analog conversion means 5 for transmitting as the audio signal SAD.

Further, according to the present invention, during the reproduction rising period from the time when the reception of the transmission signal is started to the time when the clock synchronized with the digital reception signal S2 is reproduced, the mute means 16 is operated to operate the digital video signal. DY, DP
_B , DP _R and / or the digital audio signal DAD are muted.

Further, according to the present invention, during the reproduction rising period, the first clamping means for clamping the intermediate level corresponding to the amplitude level of the received signal S1 to the reference level of the analog-digital converter and during the period other than the reproduction rising period. , A second clamping means for clamping the intermediate level included in a predetermined portion of the received signal to the reference level of the analog-digital converter, and the miute means by the control signal LOCKC for switching between the first and second clamping means. Controlled 16 miute movements.

[0012] In still yet present invention, a digital video signal Miyuto means 16 DY, DP _B, a plurality of two-input switching means 18, 19, 20 and 21 corresponding to the number of bits of the DP _R and or digital audio signal DAD formed, to one input terminal of the dual input switching means 18, 19, 20, 21, the digital video signal DY, DP _B, and inputs the DP _R and or digital audio signal DAD, the two-input switching means 18 to 21 To the other input end of Y1 to Y10, B1 to B10, R1 to R10, A1
By setting A15, arbitrary values Y1 to Y10, B1 to B10, R1 to R10, A1 during the miute operation are set.
Digital video signals DY, DP _B , DP _R according to A15
And / or the digital audio signal DAD is transmitted.

Further, in the present invention, the miute means 16
The digital video signal DY, DP _B, formed by a plurality of two-input logical product operation means corresponding to the number of bits of the DP _R and or digital audio signal DAD, to one input of the two-input AND operation means, a digital Video signals DY, DP _B , DP _R
And / or by inputting the digital audio signal DAD and by inputting the switching control signal LOCKC which falls during the reproduction rising period to the other input terminal of the two-input logical product calculating means, the digital video signal DY during the reproduction rising period. , D
P _B, and so that Miyuto the DP _R and or digital audio signal DAD.

Furthermore, in the present invention, a transmission signal receiving device 1 for receiving a transmission signal in which a video signal and / or an audio signal is encoded in a predetermined format and analog-transmitted.
At 0, the reception signal S1 obtained by receiving the transmission signal is subjected to analog-to-digital conversion to obtain a digital reception signal S2, and the digital reception signal S2 is decoded according to a predetermined format to obtain digital video signals DY, DP _B , DP.
_R and / or the reception signal decoding means 15A for transmitting the digital audio signal DAD, and the digital video signals DY, DP _B ,
Converts DP _R and or digital audio signal DAD to an analog signal, so providing a digital-to-analog converter means for transmitting a video signal and or audio signal, and a Miyuto means for Miyuto a video signal and or audio signals at a predetermined timing I chose

Further, according to the present invention, in addition to the received signal which has received the transmitted signal, the plural received signals inputted through the plural transmission media are selectively received.

[0016]

The reception signal S1 obtained by receiving the transmission signal is converted into an analog-digital signal to obtain a digital reception signal S2, and the digital reception signal S2 is decoded according to a predetermined format to generate digital video signals DY, DP _B , DP. _R
And / or when the digital audio signal DAD is transmitted, the digital reception signal S is started from the time when the reception of the transmission signal is started.
During playback rise time to clock synchronized with 2 is reproduced, the digital video signal DY, DP _B, by which is adapted to deliver by Miyuto the DP _R and or digital audio signal DAD, the user with a simple configuration The usability of can be greatly improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 10 denotes a MUSE processing apparatus as a whole applied to a television receiving apparatus according to the present invention. A baseband MUSE signal S1 FM-demodulated by a tuner of the television receiving apparatus is a MUSE signal input processing circuit. After being sample-held by the sample-hold circuit 12 through 11, converted into a MUSE signal S2 which is a digital signal by the analog-digital conversion circuit 13, and waveform-equalized by the waveform equalization circuit 14, the MUSE decoder 3
And to the voice processing circuit 4.

The MUSE decoder 3 receives the input MUSE
For the signal S2, a decoding process based on the MUSE system is executed to obtain a high-definition television signal, and the main processing circuit 15A and the MUS that perform the signal processing.
PLL circuit 1 for generating a clock synchronized with the E signal S2
It is composed of 5B.

In practice, the main processing circuit 15A generates, as a signal processing result, a high-definition television signal consisting of, for example, a 10-bit digital luminance signal DY and digital color difference signals DP _B and DP _R , which are digitally transmitted through the miuteing circuit 16. Analog conversion circuits 5A, 5B, 5
It is converted into an analog signal at C and sent as a luminance signal SY and color difference signals SP _B and SP _R.

Similarly, the voice processing circuit 4 receives the input MUS.
The audio signal of the E signal S2 is subjected to the decoding process based on the MUSE method, whereby the audio signal of 4 channels and the independent data are generated as a digital audio signal DAD of 15 to 16 bits, for example, which is passed through the digital-analog conversion circuit 8D. Converted to analog signal, audio signal SAD
Is sent as.

The PLL circuit 15B generates a clock for controlling the operation timing of the main processing circuit 15A and the entire MUSE processing device 1 based on the frame pulse and horizontal synchronizing signal included in the MUSE signal S2. Also this P
The lock state of the LL circuit 15B is configured to include the CPU, and the control signal L corresponding to the lock state of the PLL circuit 15B is set.
It is input to the control circuit 17 which controls the MUSE signal input processing circuit 11 through OCKC.

In the case of this embodiment, in the MUSE signal input processing circuit 11, the clamp level of 128/256 included in the 563 and 1125th lines of the MUSE signal is clamped to the reference center voltage VC of the analog-digital conversion circuit 13. And a rough clamp circuit that clamps the intermediate level of the amplitude level of the MUSE signal to the reference center voltage VC.

In practice, the control circuit 17 controls the control signal LOCKC.
Thus, for example, the MUSE signal S1 is clamped by the rough clamp circuit during the period from when the power is turned on or when the reception of the MUSE signal S1 is started until the PLL circuit 15B is locked, and after the PLL circuit 15B is locked, the synchronization is performed. The clamp circuit is controlled so that the PLL circuit 15B is clamped, so that the PLL circuit 15B can be quickly locked from the start of reception and stably operated.

For example, if the MUSE signal S1 is clamped by the synchronous clamp circuit while the PLL circuit 15B is not locked, a portion other than the clamp level of the MUSE signal S1 may be clamped. As a result, from the original clamp voltage. The synchronization of the PLL circuit 15B becomes unstable due to a large deviation. In this embodiment, such a problem can be prevented by switching from the rough clamp circuit to the synchronous clamp circuit for clamping as described above.

Here, in the case of this embodiment, the control circuit 1
The control signal LOCKC sent from 7 is input to the muting circuit 16 in addition to the MUSE signal input processing circuit 11. Thus, the MUSE signal S1 is clamped by the rough clamp circuit, that is, the PLL circuit 15
While B is not locked, the luminance signal SY and the color difference signals SP _B and SP _R , which are not correctly decoded, and the audio signal SAD are not correctly decoded.
To improve user-friendliness.

In practice, this miuteing circuit 16
As shown in FIG. 2, the digital luminance signal DY, the digital color difference signals DP _B and DP _R , the digital audio signal D, respectively.
A plurality of two-input switching circuits 18 and 1 according to the number of AD bits
It is configured by combining 9, 20, and 21.

The two-input switching circuits 18, 19, 20, 2
The digital luminance signal DY
Also, the respective bits of the digital color difference signals DP _B and DP _R and the digital audio signal DAD are input. The other input terminal of the two-input switching circuits 18, 19, 20, and 21 has a value Y1 preset according to the digital luminance signal DY, the digital color difference signals DP _B and DP _R , and the digital audio signal DAD.
To Y10, B1 to B10, R1 to R10, A1 to A15
Has been entered.

Also, the two-input switching circuits 18, 19, 2
0 and 21 are switched and controlled by the control signal LOCKC sent from the control circuit 17 as described above, and are actually P
While the LL circuit 15B is not locked, the digital luminance signal D
Y and digital color difference signals DP _B, DP _R, in place of the digital audio signal DAD, preset value Y1～Y10,
B1 to B10, R1 to R10, and A1 to A15 are selected. As a result, the luminance signal SY and the color difference signals SP _B and SP _{R, which} are, for example, blue back, are transmitted, and the user can easily recognize that the reception is currently under preparation.

On the other hand, the two-input switching circuits 18 and 1
When the PLL circuit 15B locks 9, 20, 21
Digital luminance signal DY and digital color difference signals DP _B , D
P _R , the luminance signal SY and the color-difference signals SP _B , S which are switched to the digital audio signal DAD and are correctly decoded as a result.
P _R and the audio signal SAD are transmitted, and the user can watch the high-definition television signal.

According to the above configuration, the MUSE decoder 3
Of the digital luminance signal DY and the digital color difference signal D until the PLL circuit 15B of the device locks to the MUSE signal S2.
P _B, DP _R, and Miyuto digital audio signal DAD, preset value Y1~Y10, B1~B10, R
1 to R10 and A1 to A15, the blue back luminance signal SY and the color difference signals SP _B and SP _R are transmitted, and the PLL
Since the miute is released at the timing when the circuit 15B is locked, it is possible to realize the MUSE processing device 1 that can significantly improve the usability of the user.

In the above embodiment, the digital luminance signal DY and the digital color difference signals DP _B and DP _R and the digital audio signal D output from the main signal processing circuit 17 are output.
Although the case where the AD is muted has been described, instead of this, the luminance signal SY and the color difference signals SP _B and SP _R and the audio signal SAD obtained through the digital-analog conversion circuit may be muted. Can be simplified.

In the above embodiment, the case where the main signal processing circuit outputs the digital luminance signal DY and the digital color difference signals DP _B and DP _R has been described.
Not limited to this, for example, even when digital color signals of R, G, B are output, the same effect as that of the above-described embodiment can be realized.

In the above embodiment, the case of receiving the MUSE signal obtained through the tuner of the television receiver is described, but the present invention is not limited to this.
Even if the MUSE signal input processing circuit selects the MUSE signal input through various media such as a video tape recorder and a cable television, the same effect as that of the above-described embodiment can be realized.

Further, in the above-mentioned embodiment, the miting circuit is constituted by the two-input selection circuit, but the present invention is not limited to this, and for example, an analog switch or a two-input logical product circuit may be used by the number of bits. . If a two-input logical product circuit is used, the digital luminance signal DY and the digital color difference signals DP _B , DP _R , and the digital audio signal D are used for one
If AD is input and the control signal LOCKC having a logic "L" level is input to the other until the PLL circuit 15B is locked, the luminance signal SY and the color difference signals SP _B and SP that become black back in the miute state are input. _R is sent out, and the same effect as the above-mentioned embodiment can be realized.

Further, in the above embodiment, MUSE
Although the digital video signal and the digital audio signal decoded from the signal are muted, the present invention is not limited to this, and even if only one of the decoded digital video signal and digital audio signal is muted. The same effect as that of the above-described embodiment can be realized.

Furthermore, in the above-mentioned embodiment, the case where the present invention is applied to the reception processing system of the MUSE signal has been described, but the present invention is not limited to this, and the point is that the video signal and / or the audio signal is in a predetermined format. It is suitable for wide application to a transmission signal receiving device that receives a transmission signal that is encoded and analog-transmitted.

[0038]

As described above, according to the present invention, a reception signal obtained by receiving a transmission signal is subjected to analog-digital conversion to obtain a digital reception signal, and the digital reception signal is decoded according to a predetermined format. When transmitting a digital video signal and / or a digital audio signal, the digital video signal and / or the digital video signal is generated during the reproduction rising period from the time when the transmission signal is received until the clock synchronized with the digital reception signal is reproduced. Since the audio signal is muted and transmitted, it is possible to realize a transmission signal receiving device that can remarkably improve the usability with a simple configuration.

[Brief description of drawings]

FIG. 1 is an MU to which a transmission signal receiving device according to the present invention is applied.
It is a block diagram which shows the structure of SE processing apparatus.

FIG. 2 is a block diagram showing a configuration of a miuteing circuit according to an embodiment.

FIG. 3 is a block diagram showing the overall configuration of a conventional MUSE processing apparatus.

[Explanation of Codes] 1 ... MUSE processing device, 2 ... MUSE preprocessing circuit,
3 ... MUSE decoder, 4 ... Voice processing circuit, 5 ...
Digital-analog conversion circuit, 11 ... MUSE signal input processing circuit, 12 ... Sample hold circuit, 13 ... Analog-digital conversion circuit, 14 ... Waveform equalization circuit, 15
A: main signal processing circuit, 15B: PLL circuit, 1
6 ... Miuteing circuit, 17 ... Control circuit, 18,
19, 20, 21 ... Two-input switching circuit.

Claims (7)

[Claims] 1. A transmission signal receiving apparatus for receiving a transmission signal in which a video signal and / or an audio signal is encoded in a predetermined format and analog-transmitted, and the reception signal obtained by receiving the transmission signal is converted into an analog signal. Received signal decoding means for obtaining a digital received signal and decoding the digital received signal according to the predetermined format to send out a digital video signal and / or a digital audio signal, and the digital video signal and / or the above at a predetermined timing. A muting means for muting a digital audio signal, and a digital-analog converting means for converting the digital video signal and / or the digital audio signal obtained through the muting means into an analog signal and transmitting the analog signal as the video signal and / or the audio signal. A transmission signal receiving device characterized by comprising . 2. The digital video signal and / or the digital video signal and / or the digital video signal by operating the mute means during a reproduction rising period from the time when the reception of the transmission signal is started to the time when a clock synchronized with the digital reception signal is reproduced. The transmission signal receiving apparatus according to claim 1, wherein the digital audio signal is muted. 3. A first clamp means for clamping an intermediate level according to the amplitude level of the received signal to a reference level of an analog-digital converter during the reproduction rising period, and during the period other than the reproduction rising period. Second clamping means for clamping an intermediate level included in a predetermined portion of the received signal to the reference level of the analog-digital converter, the control signal for switching between the first and second clamping means. 3. The transmission signal receiving device according to claim 2, wherein the miute operation of the miute means is controlled. 4. The miute means is formed by a plurality of two-input switching means according to the number of bits of the digital video signal and / or the digital audio signal, and the digital video is provided at one input end of the two-input switching means. A signal and / or the digital audio signal is input, and a preset arbitrary value is set at the other input end of the two-input switching means, so that a digital image corresponding to the arbitrary value is set during the mute operation. The transmission signal receiving apparatus according to claim 1, 2 or 3, wherein a signal and / or a digital audio signal is transmitted. 5. The miute means is formed by a plurality of two-input logical product calculating means corresponding to the number of bits of the digital video signal and / or the digital audio signal, and one input terminal of the two-input logical product calculating means. , The digital video signal and / or the digital audio signal is input, and the switching control signal falling during the reproduction rising period is input to the other input terminal of the two-input logical product calculating means, whereby the reproduction rising is performed. The transmission signal receiving device according to claim 2 or 3, wherein the digital video signal and / or the digital audio signal is muted during a period. 6. A transmission signal receiving apparatus for receiving a transmission signal in which a video signal and / or an audio signal is encoded in a predetermined format and analog-transmitted, and the reception signal obtained by receiving the transmission signal is converted into an analog signal. A reception signal decoding means for obtaining a digital reception signal and decoding the digital reception signal according to the predetermined format to send out a digital video signal and / or a digital audio signal, and the digital video signal and / or the digital audio signal. It is characterized by comprising digital-analog conversion means for converting into an analog signal and sending it out as the video signal and / or the audio signal, and a miute means for muting the video signal and / or the audio signal at a predetermined timing. Transmission signal receiving device. 7. The method according to claim 1, wherein a plurality of reception signals input through a plurality of transmission media are selectively received in addition to the reception signals that have received the transmission signals. The transmission signal receiving device according to claim 2, claim 3, claim 4, claim 5, and / or claim 6.