JPS63155986A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a chrominance signal low frequency converting color VTR capable of sending the wide band of color signal by dividing the color signal into a high frequency component and a low frequency component, applying the low frequency conversion to the low frequency component as a conventional device while leaving the high frequency component in a luminance signal, applying FM recording to both and adding them at reproduction. CONSTITUTION:The chrominance signal is separated into a C-type comb-line filter 18, subjected to band-limit by a band pass filter 19, converted by a balanced modulator 20 and a local oscillator 21, passes through a band pass filter 22 and goes to a low frequency conversion chrominance signal. On the other hand, the luminance signal is obtained by subtracting a low frequency chrominance signal from a composite color video signal inputted from an input terminal 17 at an adder 23. The luminance signal is a high frequency spectrum including a high frequency chrominance signal. The luminance signal including the high frequency chrominance signal is FM-modulated by an FM-modulator 24 and fed to an adder 25, the low frequency conversion chrominance signal is fed to the adder 25 and the result is recorded while being subjected to frequency multiplex onto the luminance signal subjected to FM modulation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recording/reproducing device such as a home VTR whose recordable frequency bandwidth is not so wide as 5 to 8 M11z.
In particular, it relates to widening the band of color signals in a low-frequency conversion color signal recording method used in signal processing circuits.

2. Description of the Related Art A conventional signal recording circuit for a VTR or the like had a configuration as shown in FIG. That is, the luminance signal of the composite color video signal input from the input terminal and having the frequency spectrum shown in FIG. The color signal is then FM modulated by an FM modulator 3 and added to an adder 4, and the color signal is separated by a bandpass filter 5 to form a frequency spectrum shown in FIG. 7, it is converted into a low-pass converted color signal, passes through a bandpass filter 8, is also added to an adder 4, is frequency multiplexed with a luminance signal, and is recorded as a signal with the spectrum shown in Figure 6.In the case of an NTSC composite color video signal , color signal subcarrier is 3.58MH
z, 4.2 MHz is used for the local oscillator 7, and the frequency of the subcarrier of the low frequency conversion color signal is selected to be 629 KHz. Further, the FM frequency of the luminance signal is selected to be 4 to 6 MHz.

The reproducing circuit has a configuration as shown in FIG. That is, the luminance signal of the composite color video signal inputted from the input terminal 9 is separated by a bypass filter 10, then FM demodulated by an FM demodulator 11 and added to an adder 12, and the color signal is separated by a bandpass filter. After being separated at 13, it is converted into the original color signal by a balanced modulator 14, a local oscillator 15, and a band pass filter 16, and then sent to an adder 12.
, and is added to the luminance signal to reproduce the original composite color video signal having the spectrum shown in FIG.

Problems that the invention seeks to solve
When used for R, the frequency of the color signal subcarrier is 629
A sufficient brightness signal band could not be obtained unless a low frequency of KHz or 1MHz or less was selected. However, if the frequency of the chrominance signal subcarrier is low, the chrominance signal band cannot be obtained sufficiently, and for example, if 629K fiz is selected, 30
The frequency ranged from about 0 to 400 Klfz, and there was a problem in that color signals exceeding the original frequency of 1 MHz could not be accurately transmitted.

The present invention solves these problems and provides a color signal low frequency conversion color VTR capable of wideband transmission of color signals.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention divides the color signal into high-frequency components and low-frequency components. Both are recorded as FM and added during playback.

According to the present invention, the high-frequency components of the color signal pass through the luminance signal processing system, and the low-frequency components of the color signal pass through the low-pass conversion color signal processing system as before, and are added up during reproduction. It is possible to realize a color signal low-frequency conversion color VTR that can reproduce high-frequency components as before and can transmit wideband signals.

EXAMPLE Hereinafter, an example of the present invention will be explained with reference to the drawings.

FIG. 1 shows a block diagram of a signal recording circuit of the present invention. That is, among the composite color video signals input from the input terminal 17 and having the frequency spectrum shown in FIG.
After becoming a signal with the frequency spectrum shown in the figure, it is band-limited by the bandpass filter 19 and becomes a low frequency color signal having the frequency spectrum shown in FIG. The signal passes through the bandpass filter 22 and becomes a low-pass converted color signal having the spectrum shown in FIG.

On the other hand, the luminance signal is obtained by subtracting the low frequency color signal shown in FIG. 9 from the composite color video signal input from the input terminal 17 and having the frequency spectrum shown in FIG.

Since this luminance signal has the band-limited chrominance signal subtracted, it becomes a frequency spectrum including a high frequency chrominance signal as shown in FIG.

The luminance signal containing this high frequency color signal is FM modulated by the FM modulator 24 and added to the adder 25, and also added to the adder 25 where the low frequency conversion color signal of the spectrum shown in FIG. 10 is FM modulated. It is frequency multiplexed with the luminance signal and recorded as a signal with the spectrum shown in FIG.

On the other hand, the reproducing circuit has a configuration as shown in FIG.

That is, the reproduced signal having the frequency spectrum shown in FIG.
9, and the color signal is separated by a bandpass filter 30, and then converted into the original low frequency color signal having the frequency spectrum shown in FIG. 9 by a balanced modulator 31, a local oscillator 32, and a bandpass filter 33. After conversion, adder 2
9 and a luminance signal containing a high frequency color signal to reproduce the original composite color video signal having the spectrum shown in FIG.

Next, other embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 14 shows a block diagram of a signal recording circuit according to another embodiment of the present invention. That is, the color signal of the composite color video signal inputted from the input terminal 34 and having the frequency spectrum shown in FIG. 4 is separated by the band pass filter 35 to become a low frequency color signal having the frequency spectrum shown in FIG. Afterwards, it is converted by a balanced modulator 36 and a local oscillator 37, and passes through a bandpass filter.
This is the low frequency conversion color signal of the spectrum shown in Figure 6. On the other hand, the luminance signal is obtained by subtracting the low frequency color signal shown in FIG. 15 from the composite color video signal input from the input terminal 34 and having the frequency spectrum shown in FIG.

Since the band-limited chrominance signal is subtracted from this luminance signal, it becomes a frequency spectrum including a high-frequency chrominance signal as shown in FIG. 17.

The luminance signal containing this high frequency color signal is FM modulated by an FM modulator 40 and added to an adder 41, and also added to the low frequency conversion color signal adder 41 of the spectrum shown in FIG. 16, where it is FM modulated. It is frequency multiplexed with the luminance signal and recorded as a signal with the spectrum shown in FIG.

In this case, the same reproducing circuit as shown in FIG. 13 is used. Further, as the local oscillator 16.31 in the reproducing circuit, a VCO controlled by an APC circuit is often used in order to correct time axis deviation during reproduction. Furthermore, it is more effective to connect a time base collector after the reproducing circuit of the present invention.

Furthermore, the present invention may be applied to a conventional color signal reproducing circuit that uses a C-type comb filter to reduce crosstalk from adjacent video tracks when reproducing a low frequency converted color signal.

Effects of the Invention As described above, according to the present invention, the frequency of the color signal subcarrier is 629 KHz in order to obtain a sufficient luminance signal band in a home VTR with a relatively low relative recording speed.
The present invention provides a color signal low frequency conversion color VTR that enables wideband transmission of color signals even when a low frequency below IMHz is selected, and can accurately transmit wideband color signals exceeding the original IMHz. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a recording and reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram of a recording section of a conventional recording and reproducing apparatus, FIG. 3 is a block diagram of a reproducing section of a conventional recording and reproducing apparatus, and FIG. The figure is a frequency spectrum diagram of a composite color video signal, Figure 5 is a frequency spectrum diagram of signals from each part of the recording/reproducing circuit in Figure 2, Figure 6 is a frequency spectrum diagram of signals to be recorded, and Figure 7 is a frequency spectrum diagram of signals from each part of the recording/reproducing circuit in Figure 2. FIGS. 8 and 9 are frequency spectrum diagrams of the reproduced signal of the reproduction circuit shown in FIG. FIG. 11 is a frequency spectrum diagram of a luminance signal including a high frequency color signal, FIG. 12 is a frequency spectrum diagram of a recorded signal, and FIG. 13 is a reproduction diagram of an embodiment of the present invention. A block diagram of the circuit, FIG. 14 is a frequency spectrum diagram of a reproduced signal in an embodiment of the present invention, and FIG.
FIG. 5 is a block diagram of another embodiment of the present invention, and FIGS.
FIG. 18 is a frequency spectrum diagram of each part of another embodiment of the present invention shown in FIG. 15. 1, 9.1? , 26.34...Input terminal,
2... Y-type comb filter, 3, 28...
・FM modulator, 4, 12゜23, 25.29.39...
... Adder, 5. 8.13.16.19°22,
30.33.35.38... Bandpass filter, 6°14, 20.3L 36... Balanced modulator, 7.15.21.32°37... Local oscillator, 10.27... Bypass filter, 11.
28...FM demodulator, 18...Y-type comb filter. Name of agent: Patent attorney Toshio Nakao and 1 other famous person 1 Figure 2 Figure 3 Figure 4 Peripheral line (MB2) Figure 5 Figure 6 Peripheral mantissa 7 section Figure 8 Peripheral 7X table (tV7Hz Figure 9 ” table (MHz) Fig. 10 Fig. 12 Fig. 14 Circular image table (/'fH1) Fig. 15 Fig. 16 Fig. 17 Fig. 18 Circular λ zero - (MH illusion

Claims (4)

[Claims] (1) Of the color signal components subjected to quadrature two-phase modulation of the composite color video signal, only the color signal low-frequency components close to the color signal subcarrier are separated and recorded, while the color signal height remaining in the luminance signal is A recording and reproducing apparatus characterized in that a luminance signal is FM modulated and recorded together with a spectral component, and is added at the time of reproduction to restore the original composite color video signal. (2) The separated color signal low-frequency components are frequency-converted to low-frequency range by a balanced modulator to become a low-frequency converted color signal, and then frequency-multiplexed with the FM-modulated luminance signal and recorded, and low-frequency conversion is performed during playback. Recording/reproduction according to claim (1), characterized in that the color signal is frequency-converted to the original color signal frequency and then added to the FM demodulated luminance signal to restore the original composite color video signal. Device. (3) By using a bandpass filter to separate the color signal from the composite color video signal and subtracting the color signal from the composite color video signal, a luminance signal containing high frequency components of the color signal is obtained. A recording/reproducing apparatus according to claim 1 or 2. (4) By using a C-type comb filter and a bandpass filter to separate the color signal low-frequency components from the composite color video signal and subtracting the color signals from the composite color video signal, the color signal high-frequency components are separated. The recording/reproducing apparatus according to claim 1 or 2, wherein the recording/reproducing apparatus obtains a luminance signal.