JPH01185091A - Video reproducing device - Google Patents

Abstract

PURPOSE:To reproduce an image with a high grade by means of a comparatively simple constitution by using a luminance signal and a carrier signal obtained from the reproducing signal of a video head, and directly generating the primary color signal of RGB. CONSTITUTION:A reproducing signal Y+C of a video head 1 is converting- processing to the RGB primary color signal necessary for a color image reproduction. At such a time, the converting processing is immediately executed from a luminance signal demodulated from the reproducing signal Y+C of the video head 1 and a low band carrier chrominance signal C extracted from the reproducing signal Y+C of the video head 1, without going through the processing stages of a frequency conversion, a mixing, a color separation, and a burst detection. Thus, the processing operation frequency of the signal can be widely omitted, and the simplification of the constitution and the picture quality improvement of a reproduced image can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is applicable to video playback devices, and furthermore, to color VTRs (
The present invention relates to a technique that is effective when applied to a color signal reproducing section of a video tape recorder (video tape recorder), and for example, a technique that is effective when applied to a video reproducing apparatus in which a VTR and a receiver are integrated.

[Prior Art] An example of the application of this type of technology is a VTR playback device described in "Television Technology January 1986 Issue" published by Denshi Gijutsu Publishing Co., Ltd., pages 39-46.

FIG. 2 shows a schematic configuration of a conventional video playback device of this type.

The video playback device 100 shown in the figure is a VH8 system VTR.
It is configured as a playback device, and includes a video head 1, an HPF (high pass filter) 2. LI'F (low pass filter), 'FM demodulation circuit 4, frequency conversion circuit 5,
It has a mixing circuit 6 and the like.

From the video head 1, the luminance signal is 3,1 MH2
A reproduced signal (Y)+ containing a carrier luminance signal (Y) that is FM modulated with a frequency shift of ~4.5 MHz and a low frequency carrier color signal (C) that is modulated with a low subcarrier of 629 KHz.
(C) is output.

HP F 2 is obtained from the above reproduced signal (Y) + (C),
A carrier luminance signal (Y), which is a high-frequency component, is extracted.

Furthermore, the LPF 2 extracts a low-frequency carrier color signal (C), which is a low-frequency component, from the reproduced signal (Y)+(C).

The FM demodulation circuit 4 demodulates the luminance signal Y from the carrier luminance signal (Y) extracted by the HPF 2. Further, the frequency conversion circuit 5 converts the frequency of the low frequency carrier color signal (C) extracted by the LPF 3 into a high frequency carrier color signal (C)' modulated with a high subcarrier of 3.58 MHz.

The mixing circuit 4 mixes the luminance signal Y and the high frequency carrier color signal (
Create a composite color video signal Y+(C)' from C)',
This is output as a reproduced color video signal.

The composite color video signal y+(c)' reproduced by the video reproduction apparatus 100 described above is also called a color composite signal, and is converted into an image by the color receiver 200.

In this case, the color receiver 200 reproduces the ROB primary color signal from the composite color video signal y+(c)', like a normal television receiver for broadcast reception.
A device with a built-in G B creation circuit 7 is used.

The RGB creation circuit 7 on the color receiver 200 side is composed of a color separation and burst detection circuit 8, a color reproduction circuit 91, a color reproduction circuit 9, and a matrix 10.

The color separation and burst detection circuit 8 separates the high frequency carrier color signal (C)' and the luminance signal Y from the composite color video signal y+(c)', and detects a burst signal if it is included in the horizontal synchronization signal. .

A color reproduction circuit 9 reproduces a blue difference signal B-Y and a red difference signal R-Y from the high frequency carrier color signal (C)'' and the burst signal. RGB primary color signals are created from the signals B-Y and R-Y.

By using this as a drive signal source for the RGB primary color picture tube 11 created as described above, a color image is reproduced.

[Problems to be Solved by the Invention] However, the inventors have found that the above-mentioned technique has the following problems.

That is, in the video playback device described above, many processes such as frequency conversion, mixing, color separation, burst detection, single color playback, and matrix processing are performed before the playback signal from the video head 1 is converted into RGB primary color signals. A processing operation is performed. For this reason, there is a problem in that image quality deterioration that occurs little by little at each processing stage accumulates, making it difficult to reproduce high-quality images. Along with this, there is also the problem that the configuration for performing many of the processing operations is complicated.

An object of the present invention is to provide a technique that enables high-quality image reproduction with a relatively simple configuration.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] Representative inventions disclosed in this application will be summarized as follows.

That is, the RGB primary color signals are directly created using the luminance signal and carrier color signal obtained from the reproduction signal of the video head.

[Operation] According to the above-described means, the number of signal processing operations can be significantly reduced. This achieves the objective of enabling high-quality image reproduction with a relatively simple configuration.

[Example] Hereinafter, a preferred example of the present invention will be described based on the drawings.

In each figure, the same reference numerals indicate the same or corresponding parts.

FIG. 1 shows a schematic configuration of a video playback device according to an embodiment of the present invention.

The video playback device shown in the figure outputs playback signals (Y) + (C) from a videotape recorded using the VH3 system.
It converts into a B primary color signal and outputs it, and includes a video head 1, HP F 2, LPF 3, FM demodulation circuit 4,
It includes an RGB creation circuit 7 and the like.

From the video head 1, a carrier luminance signal (Y) is produced by FM modulating the luminance signal with a frequency shift of 3.1 MHz to 4.5 MHz, similar to that shown in FIG.
A reproduced signal (Y)+(C) containing a low frequency carrier color signal (C) modulated with a low subcarrier of 629 KHz is output.

The HPF 2 extracts a carrier luminance signal (Y), which is a high-frequency component, from the reproduced signal (Y)+(C).

Furthermore, the LPF 2 extracts a low-frequency carrier color signal (C), which is a low-frequency component, from the reproduced signal (Y)+(C).

The FM demodulation circuit 4 demodulates the luminance signal Y from the carrier luminance signal (Y) extracted by the HPF 2.

The RGB creation circuit 7 includes a color reproduction circuit 9 and a matrix 10.
The luminance signal Y demodulated by the FM demodulation circuit 4 and the low frequency carrier color signal (C
) to create RGB primary color signals.

Here, the one-color reproducing circuit 9 receives the low-frequency carrier color signal (C) and the 629KH detected from this low-frequency carrier color signal (C).
A blue difference signal B-Y and a red difference signal RY are reproduced by the z subcarrier. 7 Trix 1o creates RGB primary color signals from the luminance signal Y and the color difference signals B-Y and R-Y.

The RGB primary color signals created by the RGB creation circuit 7 are given to the color receiver 200 as RGB format image reproduction input signals. The color receiver 200 uses this RGB
A color image is reproduced by using an input signal of the format as a driving signal source for the color picture tube 11. therefore,
On the color receiver 2oO side, ROB is output from the composite color signal.
There is no need to perform any processing to create the 3H color signal.

It is possible to reproduce a color image using the RGB primary color signals supplied from the video reproduction device 100 as they are.

In the above manner, the playback signal (Y)+ of video head 1 is
(C) can be converted into an RCiB primary color signal necessary for color image reproduction. What should be noted here is that the conversion process includes frequency conversion, mixing,
The luminance signal Y demodulated from the playback signal (Y) + (C) of the video head 1 and the playback signal (Y) + of the video head 1 without going through the processing steps of color separation and burst detection.
(C) Immediately from the extracted low-band carrier color signal (C). As a result, the number of signal processing operations can be significantly reduced, simplifying the configuration and improving the quality of reproduced images.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, it may be configured to be compatible with the Betamax method or other methods.

The above explanation has mainly been about the case where the invention made by the present inventor is applied to a video playback device, which is the background field of application, but the invention is not limited thereto. It can also be applied to color receivers that receive signals as input.

[Effects of the Invention] The effects obtained by typical inventions disclosed in this application are briefly explained below.

That is, high-quality image reproduction can be performed with a relatively simple configuration. This effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a video playback device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a schematic structure of a conventional video playback device.

Claims (1)

[Claims] 1. A demodulation circuit that demodulates a luminance signal from a reproduced signal of a video head, a filter that extracts a carrier color signal from the reproduced signal, and a luminance signal demodulated by the demodulation circuit and extracted by the filter. A video playback device comprising: an RGB generation circuit that plays back RGB primary color signals from a carrier color signal generated by the carrier color signal. 2. The video playback device according to claim 1, comprising an RGB creation circuit that plays back RGB signals using low-frequency converted carrier color signals.