JPS63250298A - Video signal recording/reproducing device - Google Patents

Abstract

PURPOSE:To simplify various kinds of signal processes of a video signal by providing a digital signal process circuit for composing reproduced luminance signal and chrominance signal so as to convert into a composite video signal and executing the signal process of the composite video signal in a special reproducing mode. CONSTITUTION:A titled device provides a Y/C output terminal 40 which can output the luminance signal and the chrominance signal with separated states and also adds the digital signal process circuit 19 which composes the reproduced luminance signal and chrominance signal so as to convert a composite signal and executes the signal process. And a selection circuit which executes various kinds of signal processes before outputting to the Y/C output terminal is provided in the digital signal process circuit 19. Namely, since the digital signal process circuit 19 which executes the signal process in the state of the composite video signal is applied, various kinds of signal processes at the time of specially reproducing can be simplified and cost-down can be enhanced, then the characteristic of Y/C separation recording/reproducing system can be kept.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a video signal recording/reproducing device suitable for separating a video signal into a luminance signal component and a color signal component and recording it on a magnetic tape or the like. It is.

[Summary of the invention]

The video signal recording/reproducing apparatus of the present invention is, for example, a video signal recording/reproducing apparatus equipped with a Y/C input terminal for inputting a signal separated into a luminance signal and a color signal.
A Y/C output terminal is provided that can output the reproduced luminance signal and color signal separately, and the reproduced luminance signal and color signal are combined and converted into a composite video signal, and the reproduced luminance signal and color signal are combined and converted into a composite video signal. a digital signal processing circuit that performs signal processing of a composite video signal, and a selection circuit that separates the signal processed by the digital signal processing circuit again into a luminance signal and a color signal and supplies them to the Y/C output terminal. It is something that

[Conventional technology]

A magnetic recording/reproducing device (VTR) capable of recording or reproducing a video signal generally separates a composite video signal into a luminance signal component and a color signal component.
The luminance signal component is frequency modulated (
(low carrier FM signal), the color signal component is converted to a low frequency, and the carrier frequency is used as a bias signal,
The information is recorded in a superimposed manner on tracks formed diagonally on the magnetic tape.

In this video signal recording/reproducing method, the color signal is converted to a low frequency band, so color unevenness is less likely to occur due to time axis fluctuations, and the luminance signal is FM modulated, so it is sufficiently stable against level fluctuations. Measures can be taken and waveform distortion is less likely to occur.

However, when outputting a composite TV signal from a TV tuner or the like and recording it on a VTR, it is first necessary to perform Y/C separation to extract color signal components from the input composite TV signal.
There is a problem in that the presence of the separation circuit degrades the quality of the luminance signal in particular.

Therefore, in the case of video signals output from television cameras, etc., which are not limited to composite video signals,
A VTR that allows recording on magnetic tape without performing Y/C separation by having a configuration (7) = VTR that allows the luminance signal and color signal to be input through separate terminals.
is proposed.

[Problem that the invention seeks to solve]

In this way, in addition to the conventional terminal for receiving composite video signals (video input terminal), there is also a terminal (Y
/C input terminal), when the luminance signal and color signal are separated as a video source, recording can be performed without going through the Y/C separation circuit by using the Y/C input terminal. image quality can be improved.

Furthermore, by making it possible to output the luminance signal and color signal in a separated state during reproduction, it is possible to prevent the characteristics of high image quality from being lost even in receiving equipment such as a television.

However, such a Y/C separation type VTR has a problem in that various processing circuits for video signals performed during special playback become complicated.

[Means for solving problems]

The present invention has been made in view of these problems.
A digital signal processing circuit that is equipped with a Y/C output terminal that can output luminance signals and chrominance signals in a separated state, and also combines the reproduced luminance signals and chrominance signals, converts them into a composite signal, and performs signal processing. A selection circuit is provided so that the signal can be outputted to the Y/C output terminal after various signal processing is performed in this digital signal processing circuit.

[Function] Since it uses a digital signal processing circuit that processes signals in the state of composite video signals, it simplifies various signal processing during special playback, reduces costs, and reduces Y/C separation. It is also possible to maintain the characteristics of the complete recording/playback method.

〔Example〕

FIG. 1 shows a video signal recording/reproducing apparatus according to the present invention.
In particular, it is a block diagram showing an embodiment of the recording system, where 10 is a video input terminal, 2o is a Y/C input terminal to which a luminance signal component and a color signal can be input individually, 30 is a video output terminal, and 4o is a Similarly, it is a Y/C output terminal that can separately output a luminance signal component and a color signal component.

IA, IB, IC, and 10 indicate switch circuits configured to switch simultaneously. For example, when selecting a composite video signal at the video input terminal 10, each switch circuit l (A, B, C, D) is manually switched. ) will fall upward. Further, when the signal of the Y/C input terminal 2o is selected, the contact piece falls downward. (In addition, the switch circuit LD may have its contacts tilted downward during playback as well.) 2 is an AGC amplifier that adjusts the level of the input video signal so that the sync chip level is constant; 3 is a brightness signal Y/C separation circuit that extracts the color signal component from the components, 4
5 is a low-pass filter with an equalizer, and 5 is a comb-shaped filter for correcting the H level difference. Further, 6 and 7 are used to form a luminance signal corresponding to the time delay and level change of the luminance signal extracted by the low-pass filter 4 etc. from the Y/C separation circuit 3, which is usually composed of an IH play line. An amplifier (6dB) and a delay circuit (440nS) are shown.

8 shows a trap circuit for removing the color subcarrier frequency component (3.58 MHz) left behind in the separated luminance signal. is configured to work when 9 is a luminance signal processing circuit that performs signal processing necessary for supplying luminance signals to the recording head, and includes, for example, a clamp circuit, an emphasis circuit, a modulation circuit, etc.; 1;
Reference numeral 1 denotes an amplifier that outputs a luminance signal before modulation.

Reference numeral 12 denotes a color process circuit that performs level adjustment and frequency conversion of color signals, and includes, for example, an ACC circuit 12A, a converter 12B, a bandpass filter 12C, and the like. The signal converted into a low frequency converted color signal at a predetermined level is then supplied to the color signal processing circuit 14, where it is combined with the luminance signal converted into an FM signal by an adder circuit 25, and sent to the recording head via an amplifier 26. supplied to

In addition, the color signal (PB/C) reproduced from a circuit not shown is supplied to the color process circuit 12 made up of an IC circuit during reproduction, and is output as a carrier color signal modulated at 3.58M HI. 15, delay circuit 1
6.

Further, the reproduced luminance signal (PB.Y) is also supplied to the comb-shaped filter 5 from a circuit (not shown) and outputted via the amplifier 11. Reference numerals 13A, 13B, and 13G indicate recording/reproduction mode changeover switches, which are controlled by control signals corresponding to the operation mode.

Switch circuit 1 for playback or recording (monitoring)
The luminance signals and color signals output from 3B and 13C are sent to switch 2 via lines L I + L 2, respectively.
3A, 23B, and further buffer amplifier 24A.
, 24B to the Y/C output terminal 40.

However, a composite video signal is formed by combining by the adder circuit 17, and the switches 18A and 18B
It is also possible to output the video to the video output terminal 30 via the video output terminal 30.

In this case, when the contact piece of the switch 18A is pushed downward, a composite television signal (E-E) outputted from a TV tuner in a VTR, for example, is selected.

Further, when the contact piece of the switch 18B is pushed down, the composite television signal is outputted via the digital signal processing circuit 19.

The digital signal processing circuit 19 includes an A/D converter, a field memory, a D/A converter, a control CPU, etc., and can digitally process video signals and skew correction during variable speed playback, for example. It is made possible.

In addition, the output of the switch circuit 18B is sent to the Y/C branch circuit 2.
The signal processed by the digital signal processing circuit 19 can be separated into a luminance signal and a color signal again. The separated luminance signal is then supplied to one terminal of the above-mentioned switches 23A and 23B via amplifiers (6 dB) 22A and 22B, and then to the Y/C output terminal 40.

Since the video signal recording/reproducing apparatus of the present invention has the above-described configuration, when a composite video signal is connected to the video input terminal 10, the switch circuit LA
By tilting the contacts of IB, IC, and LD upward, the Y/C separation circuit 3 separates the luminance signal Y and color signal C into a luminance signal Y and a chrominance signal C, as seen in the recording system circuit of a conventional VTR. Y is a low pass filter 4. Comb filter 5. The signal is supplied to a luminance signal processing circuit 9 via a trap circuit 8 . Further, the color signal extracted by the Y/C separation circuit 3 is converted into a low-frequency color signal via the color processing circuit 12 and supplied to the color signal processing circuit 14. The FM luminance signal and the low frequency converted color signal output from both signal processing circuits are supplied to the rotating magnetic head via the synthesis circuit 25 and the recording amplifier 26, and are recorded on the magnetic tape.

In addition, when the video signal is a video signal in which the luminance signal and color signal can be input separately, such as in a video camera, the Y/C input terminal 20 is used and the switch circuits LA, IB, IC, 10 are used.
By tilting the contact point downward, the brightness signal and color signal can be changed to V.
Introduced into TR.

In this case, the luminance signal Y is transmitted through an amplifier 6 with a gain of 6 dB and a delay circuit 7. and a luminance signal processing circuit 9 via a trap circuit 8 (however, the trap is inactive).
The color signal is directly supplied to the color processing circuit 14.
supplied to Therefore, since recording can be performed without passing through the Y/C separation circuit 3, there is less deterioration in recorded image quality than in the case of conventional composite video signal input.

In the device of the present invention, the regenerated luminance signal FB-Y is supplied from a circuit not shown to the comb filter 5 (which operates as a dropout compensation circuit in this case), passes through the trap circuit 8, and is demodulated by the luminance signal processing circuit 9. and switch 1
Output from 3B.

The reproduced color signal is also sent from a circuit (not shown) to the color process circuit (IC) 12, where it is converted into a carrier color signal, and then sent to the amplifier 15. Delay circuit 16. and is output via switch 13G.

Both signals are transmitted through switches 23A and 2, respectively.
3B, and is connected to the Y/C output terminal 40 in a separated state via buffers 24A and 24B, but is formed into a cobosite video signal in the synthesis circuit 17, and is connected to the video output terminal via switches 18A and 18B. 30
It is also possible to output to

Further, an E/E television signal (TV tuner output) selected by the switch 18A can also be output to this video output terminal 30.

Incidentally, in the variable speed reproduction mode, a composite signal can be outputted via the digital signal processing circuit 19 by pushing down the contact of the switch 18B.

The digital signal processing circuit 19 digitizes the composite video signal and is equipped with a memory for storing l-frame signals. Therefore, various signal processing is possible during variable speed playback or special mode playback, and still image processing is possible. You can perform image processing, frame advance, skew correction, etc.

Then, the signal that has been subjected to such signal processing is the next Y/
In the C separation circuit 21, the luminance signal and the color signal are separated again, and the amplifiers 22A, 22B, switches 23A, 23
B. Buffer 24A.

24B, it can be sent to the Y/C output terminal 40 in a separated state.

〔Effect of the invention〕

As explained above, the video signal recording/reproducing apparatus of the present invention can record/reproduce the luminance signal and color signal by inputting them separately, and can output the two signals in a separated state. /C separation video signal system can be used as a high-quality recording/playback device, and at the same time,
It has the advantage that it can also be used in composite video signal systems, and in particular, during special playback, the video signal converted to a composite signal can be processed and output by a single digital signal processing circuit. This has the effect that various signal processing of video signals is simplified.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a recording system of a VTR showing an embodiment of the present invention.

Claims (1)

[Claims] In a video signal recording/reproducing device equipped with a Y/C input terminal to which a luminance signal and a chrominance signal can be input individually, a Y/C output terminal can output the reproduced luminance signal and chrominance signal individually. , a video terminal for synthesizing the reproduced luminance signal and color signal, converting it into a composite video signal, and outputting the same; a digital signal processing circuit for performing image processing on the composite video signal in a special playback mode; A video signal recording device characterized in that a selection circuit is provided that separates the composite video signal into a luminance signal and a color signal and supplies them to the Y/C output terminal.
playback device.