JPH02194795A - Magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To make a chrominance signal band into a wide band, and to improve the quality of a picture by multiplexing the high band component of a chrominance signal to a luminance signal, and angle-modulation-recording it. CONSTITUTION:The chrominance signal inputted from an input terminal 2 is separated into a high band signal and a low band signal by a filter 27, and a burst signal is added to both the high band signal and the low band signal, and the high band component of the chrominance signal separated by the filter 27 is synthesized with the luminance signal, and is angle-modulation-recorded on a magnetic tape 13. On the other hand, the low band component of the chrominance signal is frequency-multiplex-recorded on the low band side of an angle-modulated luminance signal. Thus, the bandwidth of the chrominance signal can be expanded, and the picture quality can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording and reproducing device suitable for improving the image quality of color signals.

2. Description of the Related Art In recent years, in order to improve picture quality in home VTRs, brightness signals have been made to have a wider band. On the other hand, color signal processing has basically remained unchanged since the beginning.

FIG. 6 shows a block diagram of recording/reproducing signal processing of a conventional VTR. In the figure, 1 is an input terminal for a luminance signal, 2 is an input terminal for a subcarrier color signal, and 3 is a modulator (F
M MOD), 4 is a crystal oscillator (VXO) that generates a subcarrier frequency, and 6 is a phase comparison between the burst signal of the color signal input from the input terminal 2 and the output signal of the crystal oscillator 4, and controls the crystal oscillator 4. In the phase comparator (P, D,),
With this phase comparator 6 and crystal oscillator 4, APC/l/-
outputs a subcarrier frequency that is always phase-synchronized with the input burst signal.

6 is the horizontal synchronization signal input terminal, 7 is the voltage controlled oscillator (v
co) AFC circuit that controls the output signal frequency of s to be, for example, 40fHCfH (horizontal synchronizing signal frequency);
9 is a frequency converter that converts the subcarrier color signal to a low frequency; 10
11 is a recording amplifier circuit; 12 is a magnetic head; 13 is a magnetic tape; 14 is a magnetic head; 15 is a reproduction preamplifier;
16 is a high-frequency wave filter (HPF) that separates the angle-modulated luminance signal from the reproduced signal; 17 is an angle demodulator (FM DEM;
), 18 is a luminance signal output terminal, 19 is a bandpass filter (BPF) that separates the low-frequency converted color signal from the reproduced signal, and 2o
is a crystal oscillator circuit (VXO) that generates a subcarrier frequency,
21 is a voltage control oscillation circuit (VC○) that generates a low subcarrier frequency (for example, 40 fH); 22 is a second phase comparator that compares the phases of the burst signal of the demodulated color signal and the output signal of the crystal oscillation circuit 20; (P, D,), 23 is a second multiplier for frequency-multiplying the subcarrier frequency output from the crystal oscillation circuit 20 and the low frequency subcarrier frequency output from the voltage controlled oscillation circuit 21; 24 is a low frequency multiplier; A frequency converter demodulates a subcarrier band color signal into a subcarrier band color signal, 25 is an output terminal for the demodulated color signal, and 2θ is a first frequency converter.

The operation will be briefly explained below with reference to the drawings.

A luminance signal input from input terminal 1 is angularly modulated by modulator 3 . On the other hand, the color signal input from the input terminal 2 is sent to the frequency converter 9 on the lower side of the angle modulated luminance signal (for example, 40
fH), frequency-multiplexed with the angle-modulated luminance signal by an adder 1o, and then recorded on a magnetic tape.

In the reproduction system, the angle-modulated luminance signal is separated by a high-frequency wave filter 16, then angularly demodulated by a demodulator 17 and output to an output terminal 18. On the other hand, the low frequency converted color signal is processed by the bandpass filter 19.
After being separated into subcarrier bands, the frequency converter 24 demodulates the subcarrier band and outputs it to the output terminal 26. As described above, in the conventional recording/reproducing system, the color signal is frequency-multiplexed onto the lower frequency side of the angle-modulated luminance signal and recorded.

Problems to be Solved by the Invention However, in conventional VTRs, the color signal band is limited to about 500 KHz because the color signal is frequency multiplexed in a limited area on the low frequency side of the angle-modulated luminance signal. In recent years, the luminance signal band has improved significantly, but the chrominance signal band has remained the same, posing the problem of insufficient band.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording and reproducing device that expands the color signal band and improves image quality.

Means for Solving the Problems In order to solve the above problems, the present invention provides means for separating a subcarrier color signal into a high frequency component of the color signal and a burst signal, and a low frequency component of the color signal and a burst signal; The apparatus includes means for mixing the high-frequency component of the color signal and the burst signal with the luminance signal, and is configured to frequency-multiplex and record the angle-modulated signal and the low-frequency converted signal, respectively.

According to the above-described structure, the present invention combines the luminance signal and the burst signal and records them with angle modulation. You can get two burst signals. If the frequency converter is controlled so that the phases of these two burst signals match, the phase of the high frequency component of the color signal recorded with angle modulation and the low frequency component of the color signal recorded with low frequency conversion will be the same. They can match and can be combined with each other to reproduce the original wideband color signal.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, 27 is a filter that separates the color signal into high frequency components and burst signals, and low frequency components and burst signals;
is the high frequency component (CH) of the color signal that is the output of the filler 27
and an adder for combining the burst signal (5) with the luminance signal;
29 is a filter that separates the demodulated signal of the reproduced angle-modulated luminance signal into a high-frequency component (CH) of a color signal, a burst signal (B), and a luminance signal Y, and 3o is a filter that separates the demodulated signal from the angle-modulated luminance signal. A phase comparator (P, D,) that compares the phase of the signal and the burst signal separated from the low-frequency conversion signal.
, 31 are the high frequency component (CH) and burst signal (B) of the color signal separated from the angle modulation signal, and the low frequency component (CL) and burst signal (B) of the color signal separated from the low frequency conversion signal. This is an adder that reproduces a wideband color signal by combining the

A color signal input from the input terminal 2 is separated by a filter 27 into a high frequency signal (CH) and a low frequency signal (CL). Also, the burst signal is a high frequency signal.

It is added to both low frequency signals. An example of this fill 27 will be explained with reference to FIG. In the figure, 32 is a color signal input terminal, 33 is an amplifier, 34 is a bandpass filter whose center frequency is the subcarrier frequency and has a pass band of, for example, about ±5OOKHz, and 35 is a bandpass filter with almost the same delay characteristics as the bandpass filter 34. 36 is a subtracter that subtracts the low-frequency component of the band-limited chrominance signal that is the output of the band F-wave unit 34 from the broadband chrominance signal that is the output of the equalizer 36; A gate circuit 38 is a gate circuit which is in a conductive state during the burst signal period and in a cutoff state in other periods by the control signal BGP;
9 is an adder that adds the burst signal that is the output of the gate circuit 38 to the color signal high-frequency component that is the output of the subtracter 36;
4o is an output terminal for the low frequency component of the color signal, and 41 is an output terminal for the high frequency component of the color signal.

By subtracting the color signal band-limited by the bandpass filter 34 from the original signal as described above, the low-frequency component and high-frequency component of the color signal can be obtained, respectively.

Now, the high frequency component of the color signal separated by the filler 27 is
It is combined with the luminance signal and recorded on the magnetic tape with angle modulation. On the other hand, the low-frequency components of the color signal are frequency-multiplexed and recorded on the low-frequency side of the angle-modulated luminance signal, similar to color signal processing in conventional VTRs. During playback, the high-frequency component of the color signal recorded with angle modulation is separated by the filter 29, and combined with the low-frequency component of the color signal recorded by frequency conversion in the adder 31, and demodulated into a wideband color signal. It is output to the output terminal 26.

At this time, if the phase of the subcarrier frequency, which is the modulation frequency of the color signal, is different between the high-frequency component and the low-frequency component of the color signal, even if the adder 31 combines the two components, the original wideband color signal It is difficult to resynthesize. Therefore, the phase comparator 3o
The phase comparison is performed between the burst signal multiplexed on the high frequency component of the color signal and the burst signal multiplexed on the low frequency component of the color signal, and the oscillation of the crystal oscillator 20 is performed so that the phases of the two match. It is configured to control the frequency.

With the above configuration, a wideband color signal can be reproduced by combining the high frequency component of the color signal recorded with angle modulation and the low frequency component of the color signal recorded with low frequency conversion, resulting in a significant improvement in color signal image quality. You can expect it.

Next, other embodiments of the present invention will be described with reference to the drawings. FIG. 3 is a block diagram showing different embodiments of the reproduction system of the present invention. In the figure, 42 is a switch, and 43 is an output of the angle demodulator 17, which detects a burst signal in the demodulated luminance signal and determines whether or not the high frequency component of the color signal is multiplexed with the luminance signal during recording. This is a burst detection circuit.

In this embodiment, the burst detection circuit 43 detects the presence or absence of a burst signal in the luminance signal to control the switch 42 and the phase comparator 3o. If the high-frequency component of the color signal is not multiplexed during recording, the switch 42 is cut off to output the low-frequency component of the band-limited color signal from the output terminal 25, and the phase comparator 30
The phase comparison output of is fixed and the crystal oscillator 20 is controlled to be in the 7 rerun state. In this embodiment, by detecting the burst signal multiplexed in the luminance signal, it is determined whether the high frequency component of the color signal is multiplexed during recording, and if multiplexed, the color signal is The high-frequency component and the low-frequency component are combined to output a wideband color signal, and if multiple recording is not performed, the system switches to a conventional reproduction system.

FIG. 4 shows an embodiment of another reproduction circuit according to the present invention.

In this embodiment, the crystal oscillator 20 is in a free run state,
In order to match the phase of the subcarrier frequency between the high frequency component and the low frequency component of the color signal, the oscillation frequency of the voltage controlled oscillator 21 is controlled by the phase comparator 22.

In addition, the switch 44 outputs the output of the filter 29 when the high-frequency component of the color signal is multiplexed;
The output of the crystal oscillator 2o is switched to be input to the phase comparator 22. As explained above, according to this embodiment, the high frequency components of the color signal can be multiplexed with the luminance signal and transmitted.
It is possible to widen the color signal band, and the effect of improving image quality can be expected.

Effects of the Invention As described above, according to the present invention, the high-frequency component of the color signal can be multiplexed with the luminance signal and recorded with angle modulation.
By recombining the high-frequency component of this color signal with the band-limited color signal that is conventionally recorded with low-frequency conversion, a wideband reproduced color signal can be obtained. As a result, the resolution of the color signal can be improved, and a significant improvement in the image quality of the color signal can be expected.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a magnetic recording/reproducing device according to an embodiment of the present invention, FIG. 2 is a block diagram showing an embodiment of a filter, and FIGS. 3 and 4 are diagrams showing other embodiments of the present invention. FIG. 5 is a block diagram showing a recording/reproducing system circuit of a conventional VTR. 1... Luminance signal input terminal, 2... Color signal input terminal, 3... Angle modulator, 4......
・Crystal oscillator, 6... Phase comparator, 6...
...Horizontal synchronization signal input terminal, 7...AFC circuit, 8...Voltage control oscillator, 9...Frequency converter, 1o.A...Adder, 11. ... Recording amplifier, 12 ... Magnetic head, 13 ...
・Magnetic tape, 14...Magnetic head, 16...
...Reproduction preamplifier, 17...Angle demodulator, 18...Brightness signal output terminal, 2o...
・Crystal oscillator, 21... Voltage controlled oscillator, 22
... Phase comparator, 23 ... Frequency multiplier, 24 ... Frequency converter, 26 ... Color signal output terminal, 26 ... Frequency Multiplier, 27...
...Fill, 28...Adder, 29...
・・・Fiμari, 30...Phase comparator, 31
・・・・・・Adder. Name of agent: Patent attorney Shigetaka Awano and 1 other person 2nd
Figure 13

Claims (2)

[Claims] (1) means for separating a subcarrier color signal into a high frequency component and burst signal of the color signal and a low frequency component and burst signal of the color signal; and a means for separating the high frequency component of the color signal and the burst signal into a luminance signal. It has a means for mixing and angle modulating the color signal and a means for converting the low frequency component of the color signal and the burst signal to low frequency, and frequency multiplexes and records the angle modulated signal and the low frequency converted signal respectively. A magnetic recording/reproducing device characterized by: (2) A magnetic recording and reproducing device that demodulates and reproduces a signal obtained by frequency multiplexing an angularly modulated luminance signal and a low frequency subcarrier chrominance signal among video signals, wherein the angularly demodulated luminance signal is means for separating high-frequency components and burst signals of the luminance signal and color signals; low-frequency components and burst signals of the color signal demodulated from the low-frequency converted color signal; and high-frequency components and burst signals of the color signal. 1. A magnetic recording/reproducing device comprising means for mixing a burst signal with a burst signal.