KR0136030B1 - Self oscillating mode switchable compact disc graphic reproducing apparatus - Google Patents

Abstract

The present invention provides a self-oscillating mode switchable compact disc graphics reproducing apparatus that further provides switching means to control a color subcarrier signal applied to an RGB encoder so that the superimpose mode and the CDG internal mode can be used and switched. do.

To this end, the present invention provides a CDG decoder 1 for decoding graphic information recorded in a subcode of a CDG disc according to a predetermined synchronization signal, and an external vertical synchronizer and an external horizontal synchronizer from an external image signal provided from an external image source. A synchronization comparator 5 for detecting and separating, a phase comparator 6 for comparing the phase of the external horizontal synchronization signal from the synchronization separator 5 with the internal horizontal synchronization signal from the CDG decoder 1, A phase compensator (7) for amplifying and compensating for the phase difference detected from the phase comparator (6), and generating a reference clock of the internal horizontal synchronization signal to the CDG decoder (1) so that the internal horizontal synchronizer and the external horizontal synchronizer are identical. A switching unit 20 for applying or blocking the phase compensation control signal output from the phase compensator 7 to the oscillator 8 according to whether the oscillator 8 and the synchronization signal 10 detect the synchronization signal; Other than the synchronous detection unit 10 The reset control unit 30 outputs a reset control signal, which is a substitute for a mode discrimination signal, to the CDG decoder 1 according to whether the signal is detected, and receives a video signal from the CDG decoder 1 and displays it on a television screen. A CDG playback apparatus having an RGB encoder (2) for outputting an NTSC composite video signal; The second sub-carrier signal is outputted by blocking the internal subcarrier signal when the synchronization signal is detected from the synchronization detection unit 10, and the internal subcarrier signal is stabilized and outputted when the synchronization signal is not detected by the synchronization detection unit 10. Oscillates a predetermined subcarrier pulse based on an external video signal or an internal subcarrier signal output from the switching unit 40 and the second switching unit 12 and applies the subcarrier pulse to the RGB encoder 2. A second oscillation portion 81 '; The second switching unit 40 has a base terminal connected to the non-inverting output terminal of the synchronous detection unit 10 and turned on / off based on a level signal outputted from the non-inverting output terminal. A switching transistor Q3 for switching the processing path for the internal subcarrier signal applied to the collector terminal, and an internal subcarrier signal applied by the switching transistor Q3 connected to the collector terminal of the switching transistor Q3. A band pass filter for filtering, and a buffer for buffering the filtered internal subcarrier signal.

Description

Compact disc graphic playback device with self-oscillation mode switching

1 is a block diagram of a CDG reproducing apparatus that can be used and switched in the conventional mode.

2 is a schematic configuration diagram of a CDG apparatus capable of switching the self oscillation mode according to the present invention;

3 is a detailed circuit diagram of the switching unit shown in FIGS.

4 is a detailed circuit diagram of the reset control unit shown in FIGS.

FIG. 5 is a detailed circuit diagram of the second switching unit shown in FIG.

＊ Explanation of symbols on main part of drawing ＊

1 --- CDG decoder, 2 --- RGB encoder,

3 --- synchronous signal control means, 4 --- burst gate pulse generator,

5 --- synchronous separation, 6 --- phase comparison,

7 --- phase compensator, 8 --- oscillator,

9 --- third switching part, 10 --- synchronous detection part,

20 --- switching part, 30 --- reset control part.

The present invention relates to a compact disc graphics reproducing apparatus capable of switching the self-oscillation mode, and in particular, by providing a switching means to control the color subcarrier signal applied to the RGB encoder, the superimpose mode and the CDG internal mode can be used and switched. A self-oscillating mode switchable compact disc graphics reproducing apparatus is provided.

In general, a compact disc (CD) is not only very good in sound quality, but also has fast random access, and also enables a graphic display, since not only the audio code recorded on the disc but also an 8-bit subcode signal exist.

The 8-bit subcode signal is located in a plurality of channels P, Q, R, S, T, U, V, and W, wherein channels P and Q of the channels display random access, playback time, and track number of the CD player. The other channels R to W are used for graphic data transmission.

Currently, CDG discs are provided for the purpose of video accompaniment, oral fairytale, and educational purposes. The video accompaniment discs display only lyrics in the background color except for the beginning and end of the song. Therefore, in order to make the background video, it is necessary to superimpose the lyrics output from the CDG to an external image such as a laser disc.Only the built-in graphic function is sufficient for the storytelling or educational CDG disc and a separate external image is required. There is no need to superimpose.

Therefore, a CDG disc player with a superimpose function requires a device that can be used both in the superimpose mode and in the CDG inner mode and automatically switchable depending on whether an external video signal is input.

1 is a block diagram of a mode-compatible and switchable CDG reproducing apparatus currently proposed, wherein the CDG reproducing apparatus decodes graphic information recorded in a subcode of a CDG disc (not shown) according to a predetermined synchronization signal (1). And a synchronization separator 5 for detecting and separating an external vertical synchronizer and an external horizontal synchronizer from an external image signal provided from an external image source, an external horizontal synchronizer signal from the synchronizer 5, and the CDG decoder ( 1) a phase comparator 6 for comparing the phases of the internal horizontal synchronization signal from 1), a phase compensator 7 for amplifying and compensating the phase difference detected from the phase comparator 6, an internal horizontal synchronizer and an external horizontal An oscillator 8 for generating a reference clock of the internal horizontal synchronization signal to the CDG decoder 1 and a phase output from the phase compensator 7 depending on whether the synchronization signal from the synchronization detector 10 is detected. Bo A switching unit 20 for applying or blocking a control signal to the oscillator 8 and a reset control signal for substituting a mode discrimination signal to the CDG decoder 1 according to whether the external signal is detected by the synchronization detector 10. And a RGB encoder (2) for outputting an NTSC composite video signal capable of receiving a video signal from the CDG decoder (1) and displaying it on a television screen.

Next, the operation of the apparatus configured as described above will be described.

First, in the superimpose mode, since the external video signal is input, the synchronous detection unit 10 outputs a low level output signal (/ Q; an inverted signal of the Q signal), so that the switching unit 20 shown in FIG. The switching transistor Q1 of is turned off. At this time, the synchronization separating unit 5 receives an external image signal, separates the vertical synchronization signal and the horizontal synchronization signal, and sends the external vertical synchronization signal to the reset controller 30, and the external horizontal synchronization signal is a phase comparator ( 6). Next, the phase comparator 6 compares the external horizontal synchronizing signal with the internal horizontal synchronizing signal transmitted from the CDG decoder 1 and detects a phase difference. The phase difference detected by the phase comparator 6 is amplified and compensated for.

The oscillator 8 then oscillates by adjusting the reference clock oscillation timing for the internal horizontal synchronization signal sent to the CDG decoder 1 according to the compensated phase difference signal. At the same time, the output signal / Q of the synchronous detection unit 10 is applied to the transistor Q2 shown in FIG. 4 of the reset control unit 30, and the transistor Q2 is turned off so that the synchronous separation unit The high level external vertical synchronous signal applied at (5) is inverted by the inverter and applied to the CDG decoder 1.

Therefore, since the reset terminal of the CRT controller (not shown) in the CDG decoder 1 is activated when a low level signal is applied, the reset terminal outputs a signal necessary for superimpose operation, and the phase compensation is performed by dividing the oscillation frequency by 910. In addition to outputting a horizontal synchronous signal, an RGB encoder is used to convert image signals R, G, and B for graphic information such as characters stored in a subcode of the CDG disc and a composite synchronous signal obtained by synthesizing the internal horizontal synchronous signal and the internal vertical synchronous signal. The superimposition timing signal for determining the superimposition timing is sent to (2), and the third switching unit 19 is sent out. On the other hand, the burst gate pulse generator 4 applies the burst gate pulse to the synchronization control means 3 in synchronization with the internal horizontal synchronization signal output from the CDG decoder 1, and the applied internal subcarrier pulse Phase comparison with an external subcarrier pulse supplied from an external image source through a phase comparator, a phase compensator and an oscillator of the synchronous control means 3, and when the phase difference is detected, is external to the synchronization of the internal sub carrier pulse. The phase compensation is performed so that the synchronization of the subcarrier pulses coincide with each other. Thus, a precisely compensated subcarrier pulse of 3.579545 MHz is oscillated and applied to the RGB encoder 2.

Therefore, the RGB encoder 2 encodes the video signals R, G, and B for the graphic information output from the decoding result of the CDG decoder 1, and then outputs the graphic signal according to the phase-compensated subcarrier pulses. The switch of the third switching unit 9 is switched at high speed according to the superimposition timing signal output from the CDG decoder 1 so that the external image signal and the graphic signal are superimposed.

On the other hand, in the CDG internal mode, since there is no input of an external video signal, the synchronous detection unit 10 outputs a high level signal and is applied to the base terminal of the transistor Q1 of the switching unit 20 so that the oscillation unit is turned on. (8) becomes a free running state, and a pulse of 14.31818 MHz, which is a reference clock signal of the internal horizontal synchronization signal, is applied to the CDG decoder 1, and at the same time, the transistor Q2 of the reset controller 30 is high. The level signal is turned on and thus the low level external vertical synchronous signal outputted from the synchronization separating unit 5 is inverted by the inverter, and the high level signal is converted into the CRT controller in the CDG decoder 1. It is applied to the reset terminal of and operates as the CDG internal mode.

However, in the CDG internal mode, the oscillation portion of the synchronous control means 3 for supplying the color subcarrier signal to the RGB encoder 2 is in the free running state so that the color subcarrier signal is generated in the CDG decoder 1. Since the phase is not synchronized with the composite synchronous signal synthesized in the final output image, the screen may be flickered during mode switching.

Accordingly, the present invention has been made in view of the above situation, and further provides a switching means to control the color subcarrier signal applied to the RGB encoder to switch the self-oscillation mode so that both the superimpose mode and the CDG internal mode can be used and switched. The purpose is to provide a possible CDG playback device.

According to the self-oscillating mode switchable CDG reproducing apparatus of the present invention, a CDG decoder which decodes graphic information recorded in a subcode of a CDG disc according to a predetermined synchronization signal, and provided in an external video source. A synchronous separator for detecting and separating an external vertical synchronous signal and an external horizontal synchronous signal from an external video signal, a phase comparator for comparing the phase of the external horizontal synchronous signal from the synchronous separator with the internal horizontal synchronous signal from the CDG decoder, A phase compensator for amplifying and compensating for the phase difference detected from the phase comparator, an oscillator for generating a reference clock of the internal horizontal sync signal to the CDG decoder so that the internal horizontal synchronizer and the external horizontal synchronizer match, and a synchronization signal from the sync detector Applies or blocks the phase compensation control signal output from the phase compensator to the oscillator according to the detection. A reset control unit for outputting a reset control signal for substituting a mode discrimination signal to the CDG decoder according to whether an external signal is detected by the switching unit and the synchronization detection unit, and receiving a video signal from the CDG decoder and displaying the image signal on a television screen. A CDG playback device having an RGB encoder for outputting NTSC composite video signals; A second switching unit which blocks only an internal subcarrier signal when the synchronous signal is detected from the synchronous detector and outputs only an external video signal, and stabilizes and outputs the internal subcarrier signal when the synchronous signal is not detected by the synchronous detector; A second oscillator for oscillating a predetermined subcarrier pulse based on an external video signal or an internal subcarrier signal output from the switching unit and applying the subcarrier pulse to the RGB encoder; The second switching unit has a base terminal connected to the non-inverting output terminal of the synchronous detection unit, turned on / off based on a level signal output from the non-inverting output terminal, and applied to an internal subcarrier signal applied to the collector terminal through a resistance. A switching transistor for switching the processing path of the switching transistor, a band pass filter connected to the collector terminal of the switching transistor, for filtering the internal subcarrier signal applied by the switching transistor, and a buffer for buffering the filtered internal subcarrier signal. A compact disc graphics reproducing apparatus capable of switching oscillation modes is provided.

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

2 is a schematic configuration diagram of a CDG reproducing apparatus capable of switching the self-oscillation mode according to the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals and detailed description thereof will be omitted.

In FIG. 2, reference numeral 5 denotes a synchronization separator, 6 a phase comparator, 7 a phase compensator, 8 an oscillator, and 10, an external image signal is inputted to detect a synchronization portion to detect a high level or low level. A synchronization detector for outputting a level, 30 is a reset control unit for receiving or inverting or blocking the vertical synchronization signal of the output of the synchronous separator 5, 40 is an internal subcarrier signal and an external subcarrier signal to the output of the synchronous detector In addition, the second switching unit is configured to block the internal subcarrier pulse so that only the external video signal is input to the second oscillator 81 'when the external video signal is inputted.

Next, the operation of the present invention made of the above elements will be described in detail with reference to FIGS. 2 to 5.

First, in the superimpose mode, since there is an input of an external video signal, when the external video signal is detected by the synchronization detector 10, the output terminal Q of the synchronization detector 10 becomes a high level, and the output terminal / Q Is at the low level, and the output of the external vertical synchronization signal of the synchronous separator 5 is at the high level.

Next, the output (/ Q; low level) of the synchronous detection unit 10 is applied to the base terminal of the transistor Q2 shown in FIG. 4 of the reset control unit 30 so that the transistor Q2 is turned off. Since the external vertical synchronous signal separated from the external video signal is inverted by the inverter, the CRT controller of the CDG decoder 1 is reset because it is activated in the low level state.

At the same time, the output (/ Q; low level) of the synchronous detector 10 is also input to the base of the transistor Q1 via the resistor R1 of the switching unit 20 shown in FIG. ) Is off, so that the phase error between the external horizontal synchronization signal and the CDG internal horizontal synchronization signal is amplified and compensated by the phase compensator 6 so that the CDG internal horizontal synchronization signal can be adjusted to the external horizontal synchronization signal. The oscillation unit 8 generates an accurate clock pulse according to the horizontal synchronization signal.

On the other hand, when the output Q (high level) of the synchronization detector 10 is input to the base terminal of the transistor Q3 of the second switching unit 40 for switching the internal and external subcarrier signals, the transistor Q3 is turned on. In this state, the internal subcarrier signal applied to the bandpass filter from the CDG decoder 1 through the resistor R4 is blocked, and only the external video signal is supplied to the second oscillator 81 'and the third switch 9. The color subcarrier signal, which is input and is used as a reference for modulating the image signals R, G, and B output from the CDG decoder 1 into color signals, only outputs from the second oscillator 81 'that matches the color burst signal of the external image. By using it, the internal graphic signal and the external video signal can be faithfully displayed on the television screen.

On the other hand, in the CDG internal mode, since there is no input of an external video signal, the output (/ Q) of the synchronous detection unit 10 becomes high level and the output Q becomes low level.

Then, the output (/ Q; high level) of the synchronous detector 10 is input to the base terminal of the transistor Q2 of the reset control unit 30 so that the transistor Q2 is turned on so that the reset control unit ( The output of 30) becomes high level so that the reset terminal of the CRT controller of the CDG decoder 1 is not reset by the external vertical synchronization signal of the synchronization separating section 5.

At the same time, when the output Q (low level) of the synchronous detection unit 10 is input to the base terminal of the transistor Q3 of the second switching unit 40, the transistor Q3 is turned off, thereby the CDG decoder 1 The internal subcarrier signal divided into four by inputting the output of the oscillator 8 is a resistor R4, a band pass filter, a buffer circuit composed of a resistor and a capacitor and a capacitor not shown, and a second through a resistor R5. The output of the second oscillator 81 'is inputted to the oscillation unit 81' according to the internal subcarrier signal so that the phase of the composite synchronous signal and the color burst signal output from the CDG decoder 1 are matched. Accordingly, the internal graphics video signal output from the RGB encoder 2 is displayed on the monitor by being fixed to the terminal connected to the third switching unit 9 and the RGB encoder 2.

Therefore, according to the present invention operating as described above, the video signals R, G, and B obtained by decoding the information contained in the R to W channels of the compact disc can be converted into a signal that can be displayed on a television screen with a simplified configuration. In addition, the character information obtained from the CDG decoder can be superimposed on the external video signal, and the superimposition mode and the CDG internal mode can be combined and switched.

Claims (1)

CDG decoder 1 for decoding the graphic information recorded in the subcode of the CDG disc according to a predetermined synchronization signal, and synchronization separation for detecting and separating an external vertical synchronizer and an external horizontal synchronizer from an external video signal provided from an external video source. A phase comparison section 6 for comparing the phase of the external horizontal synchronization signal from the synchronization separating section 5 and the internal horizontal synchronization signal from the CDG decoder 1, and this phase comparison section 6 A phase compensator (7) for amplifying and compensating for the phase difference detected from the oscillator (8) for generating a reference clock of the internal horizontal synchronization signal to the CDG decoder (1) so that the internal horizontal synchronizer and the external horizontal synchronizer are coincident with The switching unit 20 and the synchronous detection unit 10 which apply or block the phase compensation control signal output from the phase compensator 7 to the oscillator 8 according to whether or not the synchronous signal is detected from the synchronous detection unit 10. Depending on whether external signal is detected A reset control unit 30 for outputting a reset control signal for the mode discrimination signal to the CDG decoder 1, and an NTSC composite video signal capable of receiving a video signal from the CDG decoder 1 and displaying it on a television screen; A CDG reproducing apparatus having an RGB encoder (2) for outputting a signal; The second sub-carrier signal is outputted by blocking the internal subcarrier signal when the synchronization signal is detected from the synchronization detection unit 10, and the internal subcarrier signal is stabilized and outputted when the synchronization signal is not detected by the synchronization detection unit 10. Oscillates a predetermined subcarrier pulse based on an external video signal or an internal subcarrier signal output from the switching unit 40 and the second switching unit 12 and applies the subcarrier pulse to the RGB encoder 2. A second oscillation portion 81 '; The second switching unit 40 has a base terminal connected to the non-inverting output terminal of the synchronous detection unit 10 and turned on / off based on a level signal outputted from the non-inverting output terminal. A switching transistor Q3 for switching the processing path for the internal subcarrier signal applied to the collector terminal, and an internal subcarrier signal applied by the switching transistor Q3 connected to the collector terminal of the switching transistor Q3. A self-oscillating mode switchable compact disc graphics playback device comprising a band pass filter for filtering and a buffer for buffering a filtered internal subcarrier signal.