KR970008643B1 - Cdg reproducing apparatus with superimposing function - Google Patents

Abstract

The CDG play device having a superimposing function having a synchronous separator 10 for separating an external horizontal synchronous signal and an external vertical synchronous signal from the external image signal applied from an external image source, a CDG decoder for decoding graphic information recorded in the sub code on the CDG disk, a phase comparing unit 30 for comparing the phase of the external horizontal synchronous signal from the synchronous separaotr 10 with the phase of the internal horizontal synchronous signal from the CDG decoder 20, a phase compensation controller 40 for controlling an oscillator 50 of oscillating the source clock of the internal horizontal synchronous signal to compensate the phase difference detected at the phase comparing unit 30, an RGB encoder 60 for encoding the color signals R, G, B on the graphic information applied from the CDG decoder 20 on the basis of the composite synchronous signal from the CDG decoder 20, and a switch 70 for switching the external image signal and the graphic signal from the RGB encoder 60 in a high speed and superimposing them according to the superimpose timing signal from the CDG decoder 20, further has a burst gate pulse generator 80 for outputting an internal color subcarrior pulse on the basis of the composite synchronous signal from the CDG decoder 20 and a synchronous signal controller 90 for receiving the internal color subcarrier pulse and controlling the external color subcarrier pulse of the external image signal to be synchronized with the internal color subcarrier pulse.

Description

CDG player with superimpose function

1 is a block diagram of a CDG player having a general superimpose function;

2 is a block diagram of a CDG reproducing apparatus having a superimpose function according to an embodiment of the present invention.

3 is a nap configuration diagram of a synchronization signal control means shown in FIG.

4 (a) to 4 (d) show an example of the result of superimposing an external video signal and an internal graphic signal based on the superimpose timing signal from the CDG decoder shown in FIG. Drawing.

* Explanation of symbols for main parts of the drawings

10: synchronization separator 20: CDG decoder

30: phase comparison unit 40: phase compensation value control unit

50: oscillator 60: RGB encoder

70: switching unit 80: burst gate pulse generator

90: synchronization signal control means

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CDG reproducing apparatus having a superimpose function. In particular, the present invention relates to an unstable signal such as a screen shake when a signal processing graphic information in a servo code on a CDG disc is superimposed with a video signal from an external video source. The present invention relates to a CDG playback device having a superimpose function that makes the screen state more stable.

Now, with the development of 'video disc' which is a composite medium of video and audio, it has been able to create a new type of software called visual music, and it is a complete system that works as a single system by combining audio and video. With the birth of / V equipment, it became a full-fledged A / V era where video and audio coexist.

As the A / V era begins in earnest, the public's attention to pure audio culture that presupposes only auditory appreciation has been gradually shifted toward the A / V culture where audio-visual coexists. As a leader of the era, it can be seen that a multi-disc player (MDP) that reads information from a disc-shaped information storage medium and reproduces a video signal and an audio signal is attracting attention.

The multi-disc player reads image information and / or audio information recorded on a disc-shaped information storage medium such as a compact disc graphic (CDG) or a laser disc (LD) to perform image signal processing and / or audio signal processing, respectively. The audio signal is output through the speaker and the video signal is displayed on the monitor.

As described above, the information storage medium employed in the multi-disc player, for example, a compact disc graphic, has not only good sound quality but also high-quality random access due to the voice code and 8-bit sub code signal recorded on the disc. And graphic displays are possible.

Here, the 8-bit subcode signal recorded on the compact disc graphic is located in the channels P, Q, R, S, T, U, V, and W. The dual P and Q channels are already used for random access and reproduction of the CDG disc player. It is used for time display and track number display, and the remaining R to W channels are used for graphic data transmission.

As such, in general, a superimpose function is widely adopted to display graphic data on a compact disc graphic, for example, lyrics data or caption data, on a monitor together with a video signal provided from an external source such as a television.

The CDG reproducing apparatus having the superimpose function generally extracts and separates an external horizontal synchronous signal and an external vertical synchronous signal from an external video signal provided from an external video source such as a television as shown in FIG. A synchronization separator 10, a CDG decoder 20 for decoding the graphic information recorded in the subcode on the CDG disc, an external horizontal synchronization signal from the synchronization separator 10, and an internal from the CDG decoder 20; Controls the phase comparator 30 for comparing the phases of the horizontal sync signal, and the oscillator 50 for oscillating the source clock of the internal horizontal sync signal in order to compensate for the phase difference detected as a result of the comparison in the phase comparator 30. An RGB encoder for encoding R, G, and B color signals for graphic information applied from the CDG decoder 20 based on the composite synchronization signal from the phase compensation value control unit 40 and the CDG decoder 20 ( 60) and a switching unit 70 for superimposing the external video signal and the graphic signal from the RGB encoder 60 at high speed according to the superimposition timing signal from the CDG decoder 20. .

The CDG playback operation by the CDG playback device having the general superimpose function configured as described above is as follows.

First, the sync separator 10 extracts and separates an external horizontal sync signal and an external vertical sync signal from an external video signal provided from an external video source such as a television. Then, the CRT controller (not shown) installed in the CDG decoder 20 is reset by the external vertical synchronous signal, and the preceding clock signal from the oscillator 50 input to the CDG decoder 20 is received. The internal horizontal synchronizing signal generated by dividing and the separated external horizontal synchronizing signal are applied to the phase comparator 30. Accordingly, the phase comparison unit 30 compares the phases of the external horizontal synchronization signal and the internal horizontal synchronization signal, and the phase compensation value control unit 40 compensates the phase difference when the phase difference is detected as a result of the comparison. For example, the oscillator 50 outputs a phase compensating control signal for adjusting the time of the clock signal oscillated by the oscillator 50, and the oscillator 50 internally synchronizes the phase error according to the phase compensating control signal. It will generate a source clock of 14.31818MHz. The CDG decoder 20 synthesizes the oscillation wave number and the internal vertical synchronous signal and is applied to the RGB encoder 60 as a composite synchronous signal. Thus, the RGB encoder 60 encodes R, G, and B color signals for graphic information output from the decoding result of the CDG decoder 20 based on the composite synchronization signal. Accordingly, the switching unit 70 transfers the external video signal from the external video source and the graphic signal (internal video signal) output from the RGB encoder 60 from the output terminal A of the CDG decoder 20. The superimposing timing signal is switched at high speed to produce a single screen (video).

According to the above-described configuration operation, the oscillation unit 50 oscillates the source clock of the internal horizontal synchronization signal in accordance with the phase compensation value control signal output from the phase compensation value control unit 40 so that the internal horizontal synchronization signal and the external horizontal synchronization signal coincide with each other. If an abnormality occurs in the source clock oscillated by the oscillator 50, the output state of the R, G and B color signals of the encoded analog analog type in the RGB encoder 60 is not good. An image that appears on the screen is not displayed correctly, but an unstable screen is displayed such as a shaking image or an unnatural color.

Accordingly, the present invention has been made in view of the above-described prior art, and an object thereof is to provide a separate synchronization signal control means in a CDG playback apparatus, and to perform an external color subcarrier pulse of an internal color subcarrier pulse and an external video signal used in an RGB encoder. The purpose of the present invention is to provide a CDG reproducing apparatus having a superimpose function that allows a more stable image to be displayed by synchronizing with the synchronous synchronization.

In order to achieve the above object, a CDG reproducing apparatus having a superimpose function according to an embodiment of the present invention is configured to extract and separate an external horizontal synchronization signal and an external vertical synchronization signal from an external image signal provided from an external image source. A separation unit, a CDG decoder for decoding graphic information recorded in a subcode on a CDG disc, a phase comparison unit for comparing an abnormality of an external horizontal synchronization signal from the synchronization separator with an internal horizontal synchronization signal from the CDG decoder, A phase compensator for controlling an oscillator for oscillating a source clock of an internal horizontal synchronizing signal so that the phase difference detected as a result of the comparison in the phase comparator is applied, and applied from the CDG decoder based on the complex synchronizing signal from the CDG decoder; R, G, B encoders for encoding R, G, B color signals for the graphic information, and super from the CDG decoder. A CDG reproducing apparatus having a switching unit for superimposing and switching an external video signal and a graphic signal from the RGB encoder at a high speed according to an impose timing signal, comprising: an internal color subcarrier based on a composite synchronous signal from the CDG decoder; A burst gate pulse generator for outputting a pulse and the internal color subcarrier pulse applied to the RGB encoder to control the external color subcarrier pulse synchronization of an external image signal to be synchronized with the internal color subcarrier pulse The synchronization signal control means is further provided.

According to a preferred embodiment of the present invention, the synchronization signal control means includes: a phase comparison unit for comparing a phase of an internal color subcarrier pulse from the burst gate pulse generator and an external color subcarrier pulse of an external video signal, and its phase And a phase compensator for controlling the phase difference detected as a result of the comparison in the comparator, and an oscillator for applying the color part carrier wave oscillated according to the phase compensator control signal from the phase compensator to the RGB encoder.

According to an embodiment of the present invention configured as described above, the synchronization signal control means performs a control operation so that the synchronization of the external color subcarrier pulse of the external video signal is synchronized with the internal color subcarrier pulse synchronously applied to the RGB encoder. The stable image is displayed.

Hereinafter, with reference to the accompanying drawings will be described the present invention in more detail.

FIG. 2 is a block diagram of a CDG reproducing apparatus having a superimpose function according to an embodiment of the present invention, in which components overlapping with those shown in FIG. 1, that is, a synchronization separator 10 and a CDG decoder ( 20), the phase comparator 30, the phase compensation value control unit 40, the oscillator 50, the RGB encoder 60, the switching unit 70 will be omitted.

Reference numeral 80 denotes a burst gate pulse generator for outputting internal color subcarrier pulses based on the composite synchronization signal output from the CDG decoder 20.

90 receives the internal color subcarrier pulse applied to the RGB encoder 60 and synchronizes the external color subcarrier pulse of an external image signal provided from an external image source such as a television in synchronization with the internal color subcarrier pulse. It is a synchronization signal control means for controlling to lose.

Here, as shown in FIG. 3, the synchronization signal control means 90 may be configured according to the phase of the internal color subcarrier pulse applied by the burst gate pulse generator 80 and the external image signal provided from the external image source. A phase comparator 90A for comparing the phases of the external color subcarrier pulses and a phase compensating control signal for outputting a phase compensation control signal so that the phase difference can be compensated if the phase difference is detected as a result of the comparison in the phase comparator 90A. Compensation value control unit 90B and an oscillation unit 90C made of, for example, a crystal oscillator for applying the color unit carrier wave oscillated in accordance with the phase compensation value control signal from the phase compensation value control unit 90B to the RGB encoder 60. do.

Referring to the CDG reproducing apparatus by the CDG reproducing apparatus having a superimpose function according to an embodiment of the present invention configured as described above is as follows.

In FIG. 2, an external video signal provided from an external video source such as a television is applied to the synchronization separating unit 10 so as to be separated into an external horizontal synchronization signal and an external vertical synchronization signal. After that, the CRT controller (not shown) installed in the CDG decoder 20 is reset by an external vertical synchronization signal, and the internal signal generated by dividing the clock signal from the oscillator 50 input to the CDG decoder 20 by 910 is generated. The horizontal synchronization signal and the separated external horizontal synchronization signal are applied to the phase comparator 30. Accordingly, the phase comparator 30 compares the phase of the external horizontal synchronizing signal with the phase of the internal horizontal synchronizing signal, and as a result, outputs from the phase compensating control unit 40 when a phase error is detected. According to the phase compensation value control signal, the oscillator 40 oscillates the clock signal of which the source clock oscillation time of the internal horizontal synchronization signal is adjusted, that is, 14.31818 MHz, so that the internal horizontal synchronization signal and the external horizontal synchronization signal coincide. Accordingly, the CDG decoder 20 divides the oscillation frequency by 910 to generate a phase-compensated internal horizontal synchronizing signal, and synthesizes the phase-compensated internal horizontal synchronizing signal and the internal vertical synchronizing signal and outputs the composite synchronizing signal. The R, G, and B color signals of the graphic information according to the decoding result are output. In addition, the CDG decoder 20 outputs the superimposition timing signal for determining the superimposition time through the output terminal A in outputting the composite synchronization signal and the R, G, and B color signals.

In this way, while the various signals are output from the CDG decoder 20, the burst gate pulse generator 80 outputs the internal color subcarrier pulses based on the composite synchronization signal output from the CDG decoder 20. The internal color subcarrier pulses are applied to the RGB encoder 60 and the synchronization signal control means 90. Accordingly, the phase comparator 90A constituting the synchronization signal control means 90 has an external color subcarrier pulse phase from the burst gate pulse generator 80 and an external image signal provided from an external video source. The phase compensation value controller 90B compares the phases of the color subcarrier pulses and the phase compensation value control unit 90B compares the phase compensation values so that the synchronization of the external color subcarrier pulses is synchronized with the synchronization of the internal color subcarrier pulses when the phase difference is detected. The oscillator 90C outputs a control signal and oscillates 3.579545 MHz, which is the color subcarrier frequency after phase compensation according to the phase compensation value control signal, to the RGB encoder 60 by applying the CDG to the CDG. After encoding the R, G, and B color signals for the graphic information outputted as a result of the decoding in the decoder 20, the color subfield after the phase compensation is correctly performed. And it outputs the graphic signal according to the frequency. Accordingly, the switch SW of the switching unit 70 is, for example, a superimposing timing output from the output terminal A of the CDG decoder 20 as shown in FIG. 4 (C). On the basis of the signal, the graphic signal (internal video signal) shown in FIG. 4 (b) is output in the sections t1 and t2, and the external video signal shown in FIG. 4 (a) is output in the sections other than t1 and t2. It is switched at a high speed as much as possible so that a video signal as shown in FIG.

As described above, according to the CDG reproducing apparatus having the super-imposing function according to the embodiment of the present invention, the external color of the external video signal to the internal color subcarrier pulse synchronously applied to the RGB encoder by the control operation of the synchronization signal control means. As the subcarrier pulses are synchronized, a more stable image is displayed compared to the conventional method in which an unstable image is displayed.

Claims (2)

A synchronization separator 10 for extracting and separating an external horizontal synchronization signal and an external vertical synchronization signal from an external image signal provided from an external image source, and a CDG decoder 20 for decoding graphic information recorded in a subcode on a CDG disc. And a phase comparison unit 30 and a phase comparison unit 30 for comparing the phase of the external horizontal synchronization signal from the synchronization separating unit 10 and the internal horizontal synchronization signal from the CDG decoder 20. A phase compensation value controller 40 for controlling the oscillator 50 for oscillating a source clock of the internal horizontal synchronization signal so that the detected phase difference is compensated, and the CDG decoder based on the composite synchronization signal from the CDG decoder 20. An external video signal and the RGB decoder 60 in accordance with an RGB encoder 60 for encoding R, G, and B color signals for graphic information applied at 20, and a superimpose timing signal from the CDG decoder 20. ) A CDG reproducing apparatus having a switching unit (70) for superimposing and superimposing a graphic signal from a burst signal, the burst gate outputting an internal color subcarrier pulse based on a complex synchronous signal from the CDG decoder (20). A pulse generator 80 and the internal color subcarrier pulse applied to the RGB encoder 60 are input to control the external color subcarrier pulse synchronization of an external image signal to be synchronized with the internal color subcarrier pulse. CDG reproducing apparatus with a superimpose function, characterized in that the synchronization signal control means 90 is further provided. 2. The phase comparator according to claim 1, wherein the synchronization signal control means (90) compares the phases of the internal color subcarrier pulses from the burst gate pulse generator (80) with the external color subcarrier pulses of the external video signal. Oscillation according to a phase compensation value control signal 90B and a phase compensation value control signal 90B which controls to compensate for the phase difference detected as a result of the comparison in the phase comparison part 90A. And an oscillator (90C) for applying the color subcarrier to the RGB encoder (60).