JPH06343180A - Television receiver provided with video signal recording and reproducing function - Google Patents

Abstract

PURPOSE:To obtain a simply constituted television receiver provided with a video signal recording and reproducing function capable of performing accurate and sure killer discrimination in entire modes with simple constitution where a video signal recording means has no voltage-controlled crystal oscillator. CONSTITUTION:At the time of recording, reference color sub carrier waves phase-synchronized with the color burst signals of input carrier chrominance signals to be recorded which are the output of the VXO 9 of a chrominance signal processing circuit 1 for television reception are used and the input carrier chrominance signals are low-band converted by a band conversion circuit 16. Further, at the time of the recording, by the result of a killer discrimination circuit 10 on a television side for discriminating the presence/absence of the color burst signals, low band converted chrominance signals are prohibited in a switching circuit 17. At the time of reproduction, the killer discrimination of reproducing carrier chrominance signals is performed in the killer discrimination circuit by using the oscillation output of a reference signal generator on a video signal reproducing side and the reproducing carrier chrominance signals are prohibited in the switching circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a built-in video signal recording / reproducing function for recording / reproducing a video signal on a recording medium.
The present invention relates to a television receiver with a video signal recording / reproducing function configured to record the same video signal as the video reproduced in T.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing a schematic structure of a television image receiving color signal processing circuit and an image signal recording color signal processing circuit of a conventional television image receiving apparatus having a video signal recording / reproducing function, and FIG. It is a figure which shows schematic structure of the reproduction color signal processing circuit. In FIG. 3, 1 is a color signal processing circuit for television reception, 2 is a video signal input terminal, 3 is a BPF for separating carrier color signals, 4 is automatic chroma level control (ACC) for controlling the amplitude of a color burst signal to be constant. ) Circuit, 5 color demodulation circuit, 6 automatic phase control (APC) circuit consisting of phase comparator 7, LPF 8 and voltage controlled crystal oscillator (VXO) 9, 11 output terminal of baseband color signal, 12 video A color signal processing circuit for signal recording, 13 is an input terminal of a video signal, 14 is a BPF for separating carrier color signals, 15 is an ACC circuit for controlling the amplitude of color signals to be constant, 16 is a low frequency conversion circuit, and 17 is a low frequency conversion circuit. A switching circuit for prohibiting the passage of the band conversion color signal by a control signal, 18 is an output terminal of the low band conversion color signal, and 19 is composed of a phase comparator 20, an LPF 21, and a voltage controlled crystal oscillator (VXO) 22. Dynamic phase control (AP
C) circuit, 23 is a killer discrimination circuit for discriminating the presence or absence of a color burst signal.

In FIG. 4, reference numeral 24 is a color signal processing circuit for reproducing a video signal, 25 is an input terminal for a reproduction low frequency conversion color signal, 26 is an ACC circuit for controlling the amplitude of the color signal constant, and 27 is a high frequency band. The conversion circuit, 28 is a BPF that limits the band,
29 is a switching circuit for prohibiting passage of a carrier color signal by a control signal, 30 is a voltage controlled oscillator (VCO), 31 is an LPF, 32 is a phase comparator, 33 is a reference signal generator, 3
Reference numeral 4 is a killer determination circuit for determining the presence / absence of a color burst signal, and 35 is an output terminal for a reproduced carrier color signal.

The recording operation of the conventional television receiver with a video signal recording / reproducing function having the above construction will be described with reference to FIG. Consider a case where the same video signal as the video reproduced on the CRT is recorded by the video signal recording means during recording. At this time, the input video signal to be recorded is input to the input terminal 2 of the television receiving color signal processing circuit 1 and applied to the BPF 3. The carrier color signal is separated in the BPF 3, and the carrier color signal is supplied to the ACC circuit 4. In the ACC circuit 4, the amplitude of the color burst signal is controlled to be constant, and a constant level carrier color signal is supplied to the color demodulation circuit 5 and the APC circuit 6. In the APC circuit 6, the color burst signal of the carrier color signal input to the phase comparator 7 and the output signal of the VXO 9 are compared in phase, and an error voltage according to the phase difference is applied to the VXO 9 through the LPF 8.
Therefore, the oscillation output signal of the VXO 9 becomes a reference color subcarrier that is phase-synchronized with the color burst signal and is supplied to the color demodulation circuit 5. Then, in the color demodulation circuit 5, the carrier color signal is demodulated into a baseband by the reference color subcarrier, and the baseband color signal is output to the output terminal 11. Then, the input video signal is reproduced on the CRT using the baseband color signal and the separately processed luminance signal.

In the color signal processing circuit of the video signal recording means, the same video signal as the video reproduced on the CRT is input to the input terminal 13 of the video signal recording color signal processing circuit 12 and applied to the BPF 14. It The BPF 14 separates the carrier color signal and supplies the carrier color signal to the ACC circuit 15. In the ACC circuit 15, the amplitude of the color burst signal is controlled to be constant, and the carrier color signal of a constant level is converted into the low frequency conversion circuit 16, the APC circuit 19, and the killer determination circuit 23.
Is supplied to. In the APC circuit 19, the color burst signal of the carrier color signal input to the phase comparator 20 and VXO2
The two output signals are compared in phase, and an error voltage corresponding to the phase difference is applied to the VXO 22 through the LPF 21. Therefore, the oscillation output signal of the VXO 22 becomes a reference color subcarrier that is phase-synchronized with the color burst signal and is supplied to the low frequency conversion circuit 16 and the killer determination circuit 23.

Then, the low-frequency conversion circuit 16 performs low-frequency conversion on the carrier color signal using the reference color subcarrier, and the low-frequency conversion color signal is applied to the switching circuit 17. The killer determination circuit 23 determines the presence / absence of a color burst signal of the input carrier color signal using the reference color subcarrier of the oscillation output of the VXO 22, and supplies the result to the switching circuit 17. The switching circuit 17 outputs the low-frequency conversion color signal to the output terminal 18 in the case of a color signal by the output of the killer discrimination circuit 23, and prohibits the output in the case of a monochrome signal.

Then, the FM modulated luminance signal created by another processing system (not shown) and the low-frequency converted color signal are frequency-multiplexed and recorded.

Next, the operation of the conventional television image receiving apparatus with a video signal recording / reproducing function during reproduction will be described with reference to FIG. In the video signal reproduction color signal processing circuit 24, the reproduction low frequency conversion color signal is supplied to the ACC circuit 26 via the input terminal 25.
Entered in. In the ACC circuit 26, the amplitude of the color burst signal is controlled to be constant, and a reproduction low-frequency conversion color signal having a constant level is supplied to the high-frequency conversion circuit 27. High frequency conversion circuit 2
7, the reproduced low-frequency conversion color signal is a voltage controlled oscillator (VC
(O) is detected using the output signal of 30, and frequency-converted into a carrier color signal of a predetermined frequency, and the carrier color signal of a predetermined frequency is separated by passing through the BPF 28. The carrier color signal is phase-compared with the switching circuit 29. It is input to the device 32 and the killer determination circuit 34. The phase comparator 32 compares the phase of the color burst signal of the carrier color signal whose frequency is converted to the high frequency band with the reference color subcarrier output from the reference signal generator 33.

The error voltage corresponding to the phase difference is L
It is applied to the VCO 30 through the PF 21, and the output signal of the VCO 30 is supplied to the high frequency conversion circuit 27. for that reason,
The carrier color signal output from the high frequency conversion circuit 27 operates so as to be in phase synchronization with the reference color sub-carrier wave output from the reference signal generator 33. The killer determination circuit 34 determines whether or not a color burst signal of the input carrier color signal is present in the reference signal generator 33.
The reference color subcarrier of the oscillating output is used for discrimination, and the result is supplied to the switching circuit 29. The switching circuit 29 is
In the case of a color signal, the reproduced carrier color signal is output to the output terminal 35 by the output of the killer discrimination circuit 34, and in the case of a monochrome signal, the output is prohibited.

Then, the reproduced carrier color signal converted into the high frequency band is input to the input terminal 2 of the television image receiving color signal processing circuit 1 shown in FIG. 3, and the reproduced carrier color signal is converted into the base band as in the recording. And reproduced on the CRT together with the reproduction luminance signal.

[0011]

By the way, in such a conventional apparatus, even when the same video signal as the video reproduced on the CRT is input to the video signal recording means at the time of recording, the same function is obtained. The television receiving means and the video signal recording means each have an automatic phase control loop constituted by a voltage controlled crystal oscillator. Therefore, the television receiver with the video signal recording / reproducing function having the above configuration requires two voltage-controlled crystal oscillators having a large circuit scale and using crystals with strict characteristic conditions, and the price has to be increased in order to realize it. It was

[0012]

In order to solve the above-mentioned problems, a television receiver with a video signal recording / reproducing function of the present invention has a color subcarrier phase-synchronized with a color burst signal of an input carrier color signal to be recorded. Is generated, the input carrier color signal is demodulated to a baseband signal by using the color subcarrier, and the input carrier color signal is converted to a low frequency band by using the color subcarrier. Frequency-converted, the low-frequency-converted color signal frequency-converted to the low frequency is recorded on the recording medium by the recording / reproducing means, and the color burst signal of the input carrier color signal is detected by the color subcarrier, It is provided with means for blocking the application of the low-frequency converted color signal to the recording / reproducing means depending on the presence or absence of the detection output.

[0013]

In the video signal recording means, the reference color subcarrier used for low frequency conversion does not need to be phase-synchronized with the color burst of the carrier color signal, and the phase difference may be arbitrary. With the above-mentioned configuration, the low-frequency conversion is performed by using the reference color subcarrier that is phase-synchronized by the television receiving means, the voltage control crystal oscillator including the crystal of the video signal recording means can be rationalized, and the price increase can be suppressed. That is why.

[0014]

EXAMPLES The present invention will be described below with reference to examples. FIG. 1 is a diagram showing a schematic configuration of a television image receiving color signal processing circuit and a recording system of the image signal recording color signal processing circuit of a television image receiving apparatus with a video signal recording / reproducing function according to an embodiment of the present invention. In the embodiment shown in FIG. 1, the same components as those in the conventional example shown in FIG. The difference between this embodiment and the conventional example is that the output signal of the VXO 9 constituting the television image receiving color signal processing circuit 1 is applied to the low frequency conversion circuit 16 of the video signal recording color signal processing circuit 12 to transfer the carrier color. The signal is converted into a low frequency conversion color signal, the APC circuit 19 in FIG. 3 is removed, and the killer discrimination circuit 10 is provided on the television image receiving color signal processing circuit 1 side, and the output of the killer discrimination circuit 10 is provided. Is applied to the switching circuit 17.

Detailed description of the same components as those of the conventional example shown in FIG. 3 will be omitted, and the different points will be described with reference to the recording operation of the television receiver with a video signal recording / reproducing function. The input video signal to be recorded is input to the television receiving color signal processing circuit 1, and the color signal demodulated to the baseband is output from the output terminal 11 as in the conventional example. Then, the output signal of the VXO 9 phase-synchronized with the color burst signal of the carrier color signal input to the phase comparator 7 is supplied to the low frequency conversion circuit 16. In the low frequency conversion circuit 16 of the video signal recording color signal processing circuit 12, the AC
The carrier color signal output from the C circuit 15 is converted into a low frequency band by the output signal from the VXO 9. Here, the BPF on the TV receiver side
3 and the BPF 14 on the video signal recording side are generally different in characteristics, the delay time is different and the low frequency conversion circuit 1
The input carrier color signal 6 and the output signal of the VXO 9 are not in phase synchronization. However, in the video signal recording means, the reference color subcarrier used for low-frequency conversion does not need to be phase-synchronized with the color burst of the carrier color signal. This is performed in the same manner as the conventional example.

However, in the television receiver with a video signal recording / reproducing function of this structure, if the same killer discrimination circuit as in the conventional case is used, the killer discrimination on the video signal recording side cannot be accurately performed. Hereinafter, this will be described with reference to FIG. 5, which is a schematic configuration diagram of a video signal recording color signal processing circuit having a killer determination circuit configuration similar to that of the conventional example.

As in FIG. 1, the output of the VXO 9 is the input terminal 3
It has been entered in 6. In the killer determination circuit 37, the ACC
The carrier color signal output from the circuit 15 and the VXO 9 output are input, the color burst signal of the carrier color signal is phase-detected, and the presence or absence thereof is determined. However, as described above, the input carrier color signal of the low frequency conversion circuit 16 and the VXO
Since the output signal of 9 is not phase-synchronized, the phase detection cannot be performed accurately, and the efficiency of the killer determination deteriorates. In particular, when the phase difference between the input carrier color signal of the low frequency conversion circuit 16 and the output signal of the VXO 9 is 90 °, killer discrimination cannot be performed.

In order to solve the above-mentioned problems, in the video signal recording color signal processing circuit of the television receiver with a video signal recording / reproducing function of the present invention, as shown in FIG. 1, a television for determining the presence or absence of a color burst signal. The output of the killer discrimination circuit 10 on the image receiving side is applied to the switching circuit 17. The switching circuit 17 outputs a low-frequency conversion color signal to the output terminal 18 in the case of a color signal by the output of the killer determination circuit 10,
In the case of a black and white signal, the output is prohibited. Therefore, the killer can be accurately determined by the above configuration.

On the other hand, it will be described that the killer discrimination malfunctions when the switching circuit 29 of FIG. 4 is operated by the output of the killer discrimination circuit 10 on the television image receiving side during reproduction. First, assuming that the killer determination circuit 10 outputs a monochrome determination result, the switching circuit 29 prohibits the output of the carrier color signal, and the input terminal 2 on the television image receiving side to which the switching circuit 29 is connected becomes no signal. That is, when the power is turned on or due to some noise, the killer discrimination circuit 10 on the television receiver side
However, once the black and white discrimination result is output, there is a problem that the system cannot recover from the black and white processing.

In order to solve the above-mentioned problems, the color signal processing circuit for video signal reproduction of the television receiver with a video signal recording / reproducing function of the present invention has the conventional configuration of FIG. 4 at the time of reproduction, and the killer discrimination circuit 34. Then, the presence or absence of a color burst signal of the input carrier color signal is determined using the reference color subcarrier of the oscillation output of the reference signal generator 33, and the result is supplied to the switching circuit 29. Then, the switching circuit 29
The output of the killer determination circuit 34 may output the carrier color signal to the output terminal 35 in the case of a color signal and prohibit the output in the case of a monochrome signal.

Needless to say, if the color processing is forcibly performed under a special condition that a black and white signal is not input, this structure is not necessary.

As described above, according to the configuration of the present embodiment, during recording, the television receiver receives the phase-synchronized reference color subcarrier, and the reference color subcarrier is used to output the low frequency band in the video signal recorder. By performing the conversion, it is possible to provide a television image receiving device with a video signal recording / reproducing function having a simple structure, which does not have a voltage-controlled crystal oscillator including a crystal of the video signal recording means. And at the time of recording, by the killer discrimination result on the television receiver side that discriminates the presence or absence of a color burst signal,
The low-pass conversion color signal is prohibited, and the reproduction carrier color signal is killer-determined by the oscillation output of the reference signal generator on the video signal reproducing side during reproduction, and the reproduction carrier color signal is prohibited. In the above, it is possible to provide a television receiver with a video signal recording / reproducing function capable of performing accurate and reliable killer determination.

Next, FIG. 2 is a diagram showing a schematic configuration of a video signal recording color signal processing circuit of a television receiver with a video signal recording / reproducing function according to a second embodiment of the present invention. In the embodiment of FIG. 2, the television image receiving color signal processing circuit has the same configuration as the television image receiving color signal processing circuit 1 shown in FIG.
In the embodiment shown in FIG. 2, the same components as those in the embodiment shown in FIG. The difference between this embodiment of FIG. 2 and FIG. 1 is that the reference signal generator 33 used during reproduction is used.
Is applied to the low-pass conversion circuit 16 to convert the carrier color signal into a low-pass conversion color signal.

The operation is basically the same as that of FIG. 1, and the frequency of the output signal of the reference signal generator 33 does not fluctuate with time so that the pull-in operation of the APC circuit during reproduction can be performed normally. Well-structured and stable,
Low frequency conversion is performed in the same manner as in the conventional example, and normal recording / reproduction can be performed. According to the configuration of the second embodiment, during recording, the output signal of the reference signal generator 33 is used to perform the low frequency conversion in the video signal recording means, thereby controlling the voltage of the video signal recording means including the crystal. It is possible to provide a television receiver with a video signal recording / reproducing function having a simple structure without a crystal oscillator.

Also in the case of the structure of FIG. 2, the problem of the color killer at the time of recording can be solved by the structure similar to that of FIG. That is, the output of the killer discrimination circuit 10 on the television image receiving side for discriminating the presence or absence of the color burst signal shown in FIG. 1 is applied to the switching circuit 17 via the input terminal 38. The switching circuit 17 outputs a low-pass conversion color signal to an output terminal 18 in the case of a color signal output from the killer determination circuit 10.
Output in the case of a black-and-white signal. Then, at the time of reproduction, the configuration of FIG. 4 as in the prior art is used, and the killer discrimination of the reproduction carrier color signal is performed on the video signal reproducing side by using the oscillation output of the reference signal generator to prohibit the reproduction carrier color signal. As in the case of the first embodiment, it is possible to provide a television receiver with a video signal recording / reproducing function capable of performing accurate and reliable killer determination in all modes.

[0026]

As described above, at the time of recording, the television receiver receives the phase-synchronized reference color subcarrier, and the reference color subcarrier is used to perform the low frequency conversion in the video signal recorder. According to the configuration of item 1 or the configuration of claim 2, wherein the carrier color signal is converted into the low-frequency conversion color signal by using the output signal of the reference signal generator of the video signal recording means, the voltage including the crystal of the video signal recording means. It is possible to realize a TV receiver with a video signal recording / playback function that does not have a control crystal oscillator. In addition, at the time of recording, low-frequency conversion is performed according to the killer judgment result on the TV receiver side that determines the presence or absence of a color burst signal. The color signal is prohibited, and at the time of reproduction, all the modes are set by prohibiting the reproduction carrier color signal by determining the killer of the reproduction carrier color signal using the oscillation output of the reference signal generator on the video signal reproducing side. There are, it is not possible to realize the superior video signal recording and reproducing via television receiving set having a simple structure which can accurately and reliably killer determination.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a television image receiving color signal processing circuit and an image signal recording color signal processing circuit of a television image receiving apparatus with a video signal recording / reproducing function according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a video signal recording color signal processing circuit of a television receiver with a video signal recording / reproducing function according to another embodiment of the present invention.

FIG. 3 is a block diagram showing a schematic configuration of a television image receiving color signal processing circuit and a video image signal recording color signal processing circuit of a conventional television image receiving apparatus with a video signal recording / reproducing function.

FIG. 4 is a block diagram showing a schematic configuration of a conventional color signal processing circuit for video signal reproduction.

FIG. 5 is a block diagram showing a schematic configuration of a video signal recording color signal processing circuit for explaining a problem of a television image receiving apparatus with a video signal recording / reproducing function in an embodiment of the present invention.

[Explanation of symbols]

 1 Color signal processing circuit for television reception 2,13 Video signal input terminal 3,14,28 BPF 4,15,26 Automatic chroma level control (ACC) circuit 5 Color demodulation circuit 6,19 Automatic phase control (APC) circuit 7 , 20, 32 Phase comparator 8, 21, 31 LPF 9, 22 Voltage controlled crystal oscillator (VXO) 10, 23, 34, 37 Killer discrimination circuit 11 Baseband color signal output terminal 12 Video signal recording color signal processing circuit 16 low frequency conversion circuit 17, 29 switching circuit 18 low frequency conversion color signal output terminal 24 video signal reproduction color signal processing circuit 25 reproduction low frequency conversion color signal input terminal 27 high frequency conversion circuit 30 voltage controlled oscillator (VCO) 33 reference signal generator 35 reproduction carrier color signal output terminal 36 reference color subcarrier input terminal 38 killer discrimination result input terminal

Claims (2)

[Claims] 1. A color subcarrier that is phase-synchronized with a color burst signal of an input carrier color signal to be recorded is created, and the input carrier color signal is demodulated into a baseband signal using the color subcarrier and projected. And a frequency conversion of the input carrier color signal to a low frequency band by using the color subcarrier,
The low-frequency-converted color signal whose frequency is converted to the low frequency is recorded on the recording medium by the recording / reproducing means, and the color burst signal of the input carrier color signal is detected by the color subcarrier, and whether the detected output is present or not. Thus, the television image receiving apparatus with a video signal recording / reproducing function is characterized in that the application of the low frequency conversion color signal to the recording / reproducing means is blocked. 2. A color subcarrier that is phase-synchronized with a color burst signal of an input carrier color signal to be recorded is created, and the input carrier color signal is demodulated into a baseband signal using the color subcarrier and projected. The input carrier color signal is frequency-converted to a low frequency band using the output of a fixed reference signal generator, and the low frequency band-converted color signal frequency-converted to the low frequency band is recorded by the recording / reproducing means. Recording on a medium, detecting the color burst signal of the input carrier color signal by the color subcarrier, and blocking the application of the low-frequency converted color signal to the recording / reproducing means depending on the presence or absence of the detection output. A TV receiver with video signal recording / playback function.