JPS59112788A - Color video signal processing circuit - Google Patents

Abstract

PURPOSE:To prevent picturization due to crosstalk and to improve recording density by compressing respective component signals of a color video signal on the time axis, and multiplexing them on time-division basis and outputting a time-series signal. CONSTITUTION:Respective component signals Y, B-Y, and R-Y constituting the composite color video signal Sin supplied to a signal input terminal 1 are compressed on the time axis by time-axis compressing circuits 4, 6 and 8 respectively and multiplexed on time-division basis by a data selector 9 in every horizontal scanning period 1H to be converted into the time-series signal. The signals Y, B-Y, and R-Y converted into the time series signal are converted into analog signals, which are FM-modulated and recorded on a magnetic tape 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides time-division multiplexing of each component signal such as a luminance signal Y and color difference signals B-Y, R, -Y, etc., which constitute a color video signal, and generates a time-return signal. The present invention relates to a color video signal processing circuit for transmission, and is applied, for example, to a magnetic recording/reproducing device that magnetically records a valley component signal on one recording trunk and reproduces a color video signal.

[Background technology and its problems]

In general, in a signal transmission system that handles high-resolution color video signals with a wide frequency band, each component such as the luminance signal Y and each color difference signal B-IY', R-Y, etc. that make up the color video signal is By providing a transmission channel for each signal, it is possible to transmit color video signals with a wide frequency band. For example, in a video recorder, multiple recording tracks are provided for each combo signal, and the luminance signal Y and each color difference signal B-Y, R
Conventionally, a system in which -Y is recorded in multiple channels has been widely used.

However, in conventional video tape recorders that record each component signal of a color video signal in multiple channels, the number of recording tracks increases as the component signals of color video signals are converted into multiple channels, resulting in a reduction in recording density. There is. Furthermore, since there is no correlation between the information recorded on adjacent recording tracks, interference due to crosstalk becomes a problem, and it is difficult to obtain a high-quality reproduction signal, especially in the case of variable speed reproduction.

Another possible method is to handle the color video signal by dividing it into frequency bands, but this method has problems such as interference occurring between each band.

[Purpose of the invention]

Therefore, in view of the above-mentioned problems in multi-channel recording video tape recorders, the present invention makes it possible to time-division multiplex each component signal constituting a color video signal and handle it as a single channel signal of a single carrier. The object of the present invention is to provide a color video signal processing circuit with a novel configuration.

[Summary of the invention]

In order to achieve the above-mentioned object, a color video signal processing circuit according to the present invention compresses each component signal constituting a color video signal in the same frequency band in the time domain, and converts each component signal compressed in the time domain into the time domain. The signal is divided and multiplexed, converted into a time series signal, and output.

[Embodiment] Hereinafter, an embodiment of the color video signal processing circuit according to the present invention will be described in detail with reference to the drawings.

1 to 3 show an embodiment in which the present invention is applied to a video tape recorder. FIG. 1 shows the configuration of a recording system signal processing circuit, and a reproduction system signal processing circuit is shown in FIG. FIG. 2 shows an example of the arrangement of takes recorded on the magnetic tape 14 on the time axis.
It is schematically shown in the figure.

In FIG. 1 showing the recording system signal processing circuit of this embodiment, a composite color video signal S in is supplied to a signal input terminal 1, and this composite color video signal Sin is supplied from the signal input terminal 1 to a color decoder 2. be done. The power rate coater 2 decodes the composite color video signal Sin and outputs each component signal constituting the composite color video signal Sin, for example, a luminance signal Y and each color difference signal B-Y.
, J(, -y is output.

The luminance signal Y collapsed by the color decoder 2 is the first
The signal is supplied to a first time-base compression circuit 4 via an analog-to-digital A/l) converter 3. The first time-base compression circuit 4 subjects the luminance signal Y digitized by the first A/D converter 3 to time-base compression processing.

Further, one color difference signal B-Y obtained by the color decoder 2 is supplied to a second time-base compression circuit 6 via a second analog-to-digital A/D converter 5, and the second time-base compression circuit 6 Time axis compression is performed in the axis compression circuit 6. Similarly, the other color difference signals R, -Y obtained by the color decoder 2 are sent to the third analog-to-digital A/D converter I.
The signal is supplied to the time axis compression circuit 8 and subjected to time axis compression.

Note that the component signals Y, 13-Y, and RY may be directly supplied to the first to third A/Di converters 3.5.7 from the video camera 18, for example. In addition, each of the above combo non-1 signals are Y, B-Y, R
-Limited to YY, ■.

Furthermore, the composite color video signal composed of each component signal may be of a standard color television system other than the NTSC system.

The first to third time axis compression circuits 4.6.
Luminance signal Y and each color difference signal B time-axis compressed in step 8
-Y and RY are supplied to the digital/analog D/A converter 10 via the take selector 9. The take selector 9 time-division multiplexes the time-axis compressed luminance signal Y and the color difference signals B-Y, RY every horizontal scanning period 11-T, and converts them into time-series signals. The luminance signal Y and the color difference signals B-Y', R converted into the above time-series signals
-Y is converted into an analog by the D/A converter 10, and F
The signal is supplied to the M converter 11, and is FM-modulated recorded on the magnetic tape 14 by the recording amplifier 12 via the recording heel N3.

In the recording system signal processing circuit having the above-mentioned expansion configuration, the first to third A/D converters 3, 5.7 receive the luminance signal Y and each color difference signal B supplied from the color encoder 2.
-Y and RY are subjected to a thin printer at the sunblink frequency required for each signal band, and the above-mentioned signals Y and B-Y are obtained.

Digitize R-Y. Here, in terms of visual characteristics, the signal band of each of the color difference signals B-Y and R-Y may be about 10 times larger than the band of the luminance signal Y. Therefore, each of the color difference signals B-Y,
The sampling frequency for converting R-Y into technology is
The sampling frequency of the luminance signal can be set to 1. In this example, 800
Clock signal CK with a clock frequency of double 80 OfH
I is supplied from the clock signal forming circuit 15 to the first A/D converter 3, and the luminance signal Y is converted into a digital signal. In addition, the horizontal frequency B I (200 times 20 Of+
(Each clock signal CK2, CK with a clock frequency of
3 from the clock signal forming circuit 15 to the second and third
A/D converters 5 and 7 are supplied with color difference signals B-Y.

R, -Y are converted into tezicles.

Further, the first to third time axis compression circuits 4°6.8
are each constituted by a technical memory, and perform time axis compression processing by reading signals at a read clock frequency higher than the write clock frequency.

In this embodiment, each of the time axis compression circuits 4°6.8
, clock signals CKl, CK2, and CK3 are supplied from the clock signal forming circuit 15 as write clock and clock signals corresponding to the valley A/D converters 3, 5.7 in the previous stage, and ]-2001 A read clock signal CK4 having a read frequency of 'n is supplied from the clock signal forming circuit 15. That is, in the first time axis compression circuit 4, the luminance signal Y converted into a signal by the first A/I) converter 3 is compressed by the clock signal CK.
(By writing at a write clock frequency of 1ji+ and reading at a read clock frequency of 1200 flI by the read clock signal CK4, the time axis of the luminance signal Y is compressed to ■. In the time axis compression circuits 6 and 8 of No. 3, each color difference signal B-Y, R
-Y is written with a write clock frequency of 200fH and read out with a readout frequency of l20Of'o, so that the time axes of each signal B-Y and R-Y are compressed into distortion, respectively. be done. Here, the above first to third
The signals Y, B-Y, and R-Y that have been time-domain compressed by the time-domain compression circuits 4 and 6.8 are read out at the same readout clock frequency of 1200 fu, so the D/A converter 10, each signal has the same frequency band.

Note that each clock signal CK used in the above time axis compression process
1. It goes without saying that each of the frequencies CK2, CKa, and CK4 may be changed to other frequencies.

Further, the data selector 9 sequentially selects each of the time-axis compressed component signals Y, B-Y, and R-Y in accordance with the select clock signal CK5 supplied from the clock signal forming circuit 15. By doing so, the signals are time-division multiplexed to form a time-series signal with a take arrangement as shown in FIG.

Each component signal Y converted to the above time series signal
, 13-Y, R, -Y can be transmitted as l-channel signals, and are FM modulated and recorded on the rack 11 of the magnetic tape 14 using a single carrier.

As described above, each component signal Y, B-Y, and R-Y constituting the composite color video signal is compressed on the time axis into the same frequency band, time-division multiplexed, and recorded with FM modulation on the magnetic tape 14. In the example, the reproduction system signal processing circuit can reproduce the composite color video signal by performing signal processing in a process reverse to that of the recording system signal processing circuit.

That is, the second section showing the reproduction system signal processing circuit of this embodiment
In the figure, the reproduction time-series signal reproduced from the magnetic tape 14 by the reproduction head 21 is transmitted to the F
After being supplied to the M demodulator 23 and modulated, it is converted into a digital signal by the analog-to-digital A/D converter 24. Then, the playback time-series signal converted into a digital signal is processed by the take selector 25 into each component signal Y, B-Y, I(,-Y
The first to third time axis expansion circuits 26°2
Written on 8.30. Here, the A/D converter 24
and O. Each time axis expansion circuit 26, 28.30 has the same read clock frequency as each time axis compression circuit 4, 6.8 described above.] The clock signal with the write clock frequency of 200fl+ is the reproduced clock signal forming circuit 34. Supplied from.

The luminance signal Y is then transmitted from the first time axis expansion circuit 26 to 801. (By being read out at the readout clock frequency of Y is returned to the normal time axis by being read out from the second and third time axis expansion circuits 28°30 at a read clock frequency of 20 OfH, respectively.
2nd゜3rd digital analog 1)/A converter 29.3
1, each is converted to analog.

Further, the valley component signal Y is converted into an analog signal by each of the D/A converters 27, 29, and 31.

B-YJ-Y is supplied to the color encoder 32.

The color encoder 32 generates a composite color video signal S from the component signals Y, B-Y, and R-Y.

ut is formed and outputted from the signal output terminal 33.

It is also possible to supply -Y and RY to a matrix circuit 37 and form three primary color signals JB and G in this matrix circuit 37, so that the monitor television reception PA 38 can be activated by the three primary color signals R, B and G.

In the embodiment described above, each of the component signals Y, B-YJ-Y constituting the composite color video signal Vin supplied to the signal input terminal 1 of the recording system signal processing circuit is time-axis compressed and time-divided. By converting the signal into a time series signal through multiplexing, it can be transmitted as a single channel signal, and single carrier YM modulation recording can be performed on one trunk of the magnetic tape 14. Moreover, the time-division multiplexed component signals Y, B-Y, and R-Y have the same frequency band due to the above-mentioned time axis compression, so that the recording density on the magnetic tape 14 can be maximized. It can be made higher. Furthermore, even when a so-called helical scan method is adopted and one field's worth of color video signals is recorded on each recording trans 21 that is inclined with respect to the tape running direction, there is no correlation in information between adjacent trunks. Therefore, there is extremely little signal deterioration due to the cross I-reflection component, and a high quality reproduction signal can be obtained even during variable speed reproduction.

Note that the present invention is not limited to the above-described embodiments, and can be applied to various signal transmission systems other than magnetic recording and reproducing systems, such as video tape recorders, and can also be applied to various signal transmission systems such as video tape recorders. Various standard television systems such as NTSC and PAL systems may be used. Also,
In the above embodiment, time axis processing was performed on each component signal using digital memory, but CCD (Cha
It is also possible to perform time-axis processing using an analog shift register formed by a device such as a rgeCoupled Device.

〔Effect of the invention〕

As is clear from the description of the embodiments described above, the color video signal processing circuit according to the present invention compresses the component signals constituting the color video signal in the same frequency band on the time axis, and Since each component signal is time-division multiplexed, converted into a time-series signal, and output, each component signal can be transmitted as a single channel signal having the same frequency band, and can be applied to video tape recorders, etc. As a result, it is possible to increase the recording density and prevent deterioration in image quality due to crosstalk between adjacent tracks, thereby making it possible to record and reproduce high-resolution color video signals with good image quality.

Therefore, according to the present invention, the intended purpose can be fully achieved.

[Brief explanation of the drawing]

1 to 3 show an embodiment in which the present invention is applied to a video tape recorder, FIG. 1 is a block diagram of a recording system signal processing circuit, and FIG. 2 is a block diagram of a reproduction system signal processing circuit. FIG. 3 is a schematic diagram showing the arrangement of the takes to be transmitted.

Claims (1)

[Claims] It is characterized by compressing the time axis of each combo component signal constituting the color video signal into the same frequency band, and time-division multiplexing the time-axis compressed component signals to convert them into time-series signals and outputting them. color video signal processing circuit.