JPH08322008A - Disk reproducing device - Google Patents

Abstract

PURPOSE: To generate a composite video signal in the reproduction of a CD-G disk as one in a non-interlace scanning system by taking out simultaneously two kinds of composite video signals with different television systems to take out simultaneously. CONSTITUTION: Composite video signal generation circuits 5, 6 are set so as to be switched to an external synchronous mode to perform signal processing synchronizing with an external video signal of interlace scanning system and an asynchronous mode to perform the signal processing without synchronizing with the external video signal. The composite video signal generated by the composite video signal generation circuits 5, 6 is converted into the one of another television system by setting the external synchronous mode, and also, video data of non-interlace scanning system is generated as the composite video signal of non-interlace scanning system by the composite video signal generation circuits 5, 6 by setting the asynchronous mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc reproducing apparatus for reproducing a disc on which a video signal of a non-interlaced scanning system is recorded, and more particularly to a disc reproducing apparatus suitable for reproducing a CD-G compatible disc.

[0002]

2. Description of the Related Art In a disc reproducing apparatus for a video disc on which a video signal is recorded, it is necessary to output a composite video signal corresponding to the NTSC or PAL system according to the television system of a television monitor. Therefore, as a disc playback device, multiple composite images compatible with different TV systems can be used so that it can be used in areas where multiple TV systems are mixed, or a common model can be used for different destinations of different TV systems. A signal may be output.
In such a disc reproducing apparatus, for example, NT
In the case of outputting both SC and PAL type composite video signals, the NTSC type composite video signal is output because an NTSC type compatible disc is mainly used and the NTSC type composite video signal is output. PA with a television system conversion circuit for converting to a composite video signal
It is also possible to output L-type composite video signals.

By the way, as a disc on which a video signal is recorded, there is a graphic-compatible CD-G disc in which video data is recorded by using a subcode of a CD type disc, and as a disc reproducing device, an ordinary video is used. In addition to discs, many CD-G discs are also playable.

According to the standard, the video data of this CD-G disc is recorded in conformity with the non-interlaced scanning system with even lines. Therefore, in the CD-G compatible disc reproducing apparatus capable of reproducing the CD-G disc, C
When the D-G disc is played back, the video data is signal-processed according to the standard, and a non-interlaced scanning composite video signal with even lines is output. Ie CD
-The composite video signal obtained when reproducing the G disc is different from the composite video signal of the television system in the scanning system.

Therefore, in a CD-G compatible disc reproducing apparatus, when a composite video signal corresponding to a television system different from the video signal of the disc is output by using a television system converting circuit, the disc to be reproduced is a CD-G. In the case of a disc, it is necessary to regenerate a composite video signal so as to convert the non-interlaced scanning system to the interlaced scanning system, and then convert the composite video signal into a composite video signal corresponding to a different television system by the television system conversion circuit.

[0006]

By the way, flicker occurs on a video screen displayed by a composite video signal of the interlaced scanning system due to the characteristics of the scanning system. Therefore, as described above, in the disc reproducing apparatus equipped with the television system converting circuit, the composite video signal converted into the interlaced scanning system is generated even when the CD-G disc is reproduced, so that the non-interlaced scanning is performed. The screen is different from the original flicker-free image screen.

According to the present invention, in a disc reproducing apparatus equipped with a television system conversion circuit, when a CD-G disc is reproduced, a video screen without the flicker feeling inherent in the non-interlaced scanning system is displayed.

[0008]

SUMMARY OF THE INVENTION The present invention is a composite video signal generation circuit for demodulating video data read from a disk to generate a composite video signal conforming to a predetermined television system, and the composite video signal generation circuit. A television system conversion circuit that converts a composite video signal from the circuit into a composite video signal that conforms to another television system, and a video signal generation circuit that generates an interlaced scanning system video signal for displaying a specific video screen, The composite video signal generation circuit is configured to generate a composite video signal without being synchronized with the external synchronization mode in which the composite video signal is generated in synchronization with the video signal generated from the video signal generation circuit. It is provided with an asynchronous mode for performing, and the external synchronous mode and the asynchronous mode can be selectively set.

[0009]

The present invention focuses on the fact that even in a disc reproducing apparatus capable of outputting a plurality of composite video signals corresponding to different TV systems, the main TV system is biased to one side, and the combination of the main TV systems is When only the video signal is used, when the non-interlaced scanning type video data read from the disc is reproduced, the composite video signal generation circuit performs the signal processing in synchronization with the external video signal of the interlaced scanning type. Switch to a mode in which signal processing is performed without synchronizing with the video signal. By doing so, it becomes impossible to generate the composite video signal of the other minor television system, but the CD-
The generation of the composite video signal at the time of reproducing the G disc is now performed in the non-interlaced scanning system, and the CD
-It is possible to output the composite video signal of the original non-interlaced scanning method of the video data of the G disc.

[0010]

1 is a circuit block diagram showing an embodiment of the present invention, in which 1 is an input terminal to which a digital signal obtained by waveform-shaping an RF signal read from a CD-G disc is inputted, 2 Is the digital signal input to the input terminal 1
EFM demodulation circuit for FM demodulation, 3 is the EFM demodulation circuit 2
The sub-code separation circuit 4 for separating a sub-code signal from the digital signal demodulated by the EFM by 4 is NT from the sub-code signal separated by the sub-code separation circuit 3.
It is a CD-G signal processing circuit for generating a composite video signal of the SC system.

The CD-G signal processing circuit 4 converts the video data recorded on channels R to W of the subcode signal to R.
A subcode decoder 5 for demodulating into a GB signal and an NTS from the RGB signal demodulated by the subcode decoder 5
NTSC encoder 6 for generating C-system composite video signal
And a timing control circuit 7 for controlling the generation timing of various timing pulses necessary for signal processing by the subcode decoder 5 and the NTSC encoder 6.

Reference numeral 8 is an NTSC output terminal for deriving an NTSC composite video signal output from the NTSC encoder 6, and 9 is a PAL composite video signal of the NTSC composite video signal output from the NTSC encoder 6. The television system conversion circuit 9 converts the NTSC system composite video signal into an NTSC decoder 10 that obtains an RGB signal output, and an RGB signal output from the NTSC decoder 10. , PAL for generating composite video signal of PAL system
And an encoder 11.

Reference numeral 12 is a PAL for deriving a PAL system composite video signal output from the PAL encoder 11.
Output terminal. Reference numeral 13 is a video disc video processing circuit used for reproducing a video disc on which an NTSC composite video signal is recorded by an analog signal, and 14 is a blue back display of an NTSC television monitor screen provided in the video processing circuit 13. A blue back image generating circuit for generating a blue back image signal for controlling an NTSC by the composite image signal generating circuit 4 from the blue back image signal output from the blue back image generating circuit 14.
It is a pulse generation circuit that generates various timing pulses necessary for generating a composite video signal of the method.

The pulse generation circuit 15 separates horizontal / vertical sync signals and color burst signals included in the blue-back video signal, and horizontal timing is generated according to the respective generation timings of the separated horizontal sync signals and vertical sync signals. Pulse and vertical timing pulse respectively on the first terminal 1
6 and the second terminal 17, and the horizontal and vertical synchronizing signals are used to generate the horizontal synchronizing clock pulse and the composite synchronizing clock pulse from the third terminal 18 and the fourth terminal 19, respectively, and the color burst signal is used. A burst synchronization clock pulse with crystal oscillation accuracy is generated from the fifth terminal 20.

Reference numerals 21 and 22 are switches for selectively supplying the horizontal timing pulse and the vertical timing pulse from the pulse generating circuit 15 to the timing control circuit 7, and 23 is a switch between the horizontal synchronizing clock pulse and the burst synchronizing clock pulse. The switch 24 is a switch for supplying the sub-code decoder 5 and the timing control circuit 7, and the switch 24 is a switching control circuit for switching the switches 21, 22 and 23.

Next, the operation of the disc reproducing apparatus configured as described above will be described. When the digital signal read from the CD-G disc is input to the input terminal 1, the digital signal is EFM demodulated by the EFM demodulation circuit 2,
Then, the subcode separation circuit 3 separates the subcode signal. The video data recorded on the separated R to W channels of the subcode signal is demodulated into RGB signals by the subcode decoder 5 and then converted into an NTSC composite video signal by the NTSC encoder 6.

The composite video signal output from the NTSC encoder 6 is derived from the NTSC output terminal 8 and supplied to the television system conversion circuit 9. The composite video signal supplied to the television system conversion circuit 9 is converted into an RGB signal by the NTSC decoder 10 and then PAL.
It is encoded by the encoder 11 and is regenerated into a PAL composite video signal.

By the way, the subcode decoder 5 and NT
The signal processing by the SC encoder 6 is performed by the switches 21 and 2.
Depending on the switching state of 2 and 23, the external synchronous mode and the asynchronous mode are selectively performed.

When the external synchronization mode is set, the switching control circuit 24 closes the switches 21 and 22, and the switch 23 outputs the horizontal synchronization clock output from the third terminal 18 of the pulse generation circuit 15 as shown in the figure. The state is switched to select a pulse.

In this state, the various pulses supplied to the sub-code decoder 5 and the NTSC encoder 6 are NT generated by the blue-back video generation circuit 14.
It is generated based on the SC system interlaced scanning system blue-back video signal, and the timing control circuit 7 adjusts the timing. Therefore, signal processing by the sub-code decoder 5 and the NTSC encoder 6 is performed based on the horizontal / vertical synchronizing signals and the color burst signal included in the blueback video signal, and horizontal / vertical timing pulses and horizontal synchronizing clocks. This is performed in synchronization with the pulse and burst synchronization clock pulses, and as a result, the NTSC encoder 6 outputs a composite video signal of the interlaced scanning system conforming to the NTSC system.

In this case, since the composite video signal supplied to the television system conversion circuit 9 is the interlaced scanning system based on the NTSC system, the NTSC decoders 10 and P are used.
The AL encoder 11 performs the desired signal processing and PAL
From the output terminal 12, a composite video signal of the interlaced scanning system based on the PAL system is derived.

Therefore, the subcode decoders 5 and N
In the state where the signal processing by the TSC encoder 6 is set to the external synchronization mode, a composite video signal of the interlaced scanning system but the NTSC system is derived from the NTSC output terminal 8 and at the same time, the PA signal is output from the PAL output terminal 12.
An L-system composite video signal is derived.

On the other hand, when the asynchronous mode is set,
The switching control circuit 24 opens the switches 21 and 22, and the switch 23 is switched to a state of selecting the burst synchronization clock pulse output from the fifth terminal 20 of the pulse generation circuit 15.

In this state, the timing control circuit 7
Only the burst synchronization clock pulse of crystal oscillation accuracy is supplied to the timing control circuit 7, and the timing control circuit 7 creates various pulses necessary for generating the composite video signal from the video data based on the burst synchronization clock pulse. Come to do. Therefore, the subcode decoder 5 and NT
The signal processing by the SC encoder 6 is performed only in synchronization with the burst sync clock pulse, and as a result, the NTSC encoder 6 outputs the composite video signal as it is in the non-interlaced scanning method according to the video data recorded on the disc. Will be done.

Therefore, the subcode decoders 5 and N
In the state where the signal processing by the TSC encoder 6 is set to the asynchronous mode, the NTSC output terminal 8 outputs the original NTSC composite video signal of the non-interlaced scanning system recorded on the disc.

However, in this asynchronous mode, since the composite video signal supplied to the television system conversion circuit 9 is a non-interlaced scanning system, the NTSC decoder 10 is used.
Also, the PAL encoder 11 does not perform the intended signal processing, and it becomes impossible to derive the PAL system composite video signal from the PAL output terminal 12. Therefore, when deriving a PAL system composite video signal from the PAL output terminal 12, the signal processing by the subcode decoder 5 and the NTSC encoder 6 must be set to the external synchronization mode.

On the other hand, when the PAL system composite video signal from the PAL output terminal 12 is not required, the synchronous mode setting of the signal processing by the subcode decoder 5 and the NTSC encoder 6 may be either the external synchronous mode or the asynchronous mode. However, in order to display the recorded image of the CD-G disc on the original non-interlaced scanning type image screen, the asynchronous mode is usually set.

The setting switching between the external synchronous mode and the asynchronous mode may be performed manually, or it may be detected that a connection cord is connected to the PAL output terminal 12, and the external synchronous mode may be set when the connection is detected. Other than that, if the asynchronous mode is set, automatic switching is possible.

[0029]

As described above, according to the present invention, the composite video signal generation circuit synchronizes with the external video signal of the interlaced scanning system when reproducing the video data of the non-interlaced scanning system read from the disk. Since it is possible to switch from the signal processing mode to the signal processing mode without synchronizing with the external video signal, when using only the composite video signal of the main TV system, the reproduction of the CD-G disc is performed. Occasionally, the composite video signal is generated in the non-interlaced scanning system, and the video data of the CD-G disc can be displayed as a flicker-free video screen of the non-interlaced scanning system.

Further, according to the present invention, in order to obtain a composite video signal conforming to a television system different from the video data recorded on the disc, the same television data as the video data once recorded on the disc is used. Since a composite video signal conforming to the system is generated and then the composite video signal is converted to the television system, the composite video signal is generated by the interlaced scanning system when the CD-G disc is reproduced. 2 different TV systems
It is possible to provide a disk device capable of simultaneously extracting various types of composite video signals and supporting an area in which a plurality of television systems coexist, or a common model corresponding to a destination of a different television system. Further, in this case, since the color back signal generating circuit for displaying the monitor screen in a state other than the reproduction of the disc is used as the video signal generating circuit, the video signal generating circuit needs to be specially provided. Therefore, the increase in the number of constituent circuits can be suppressed.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention.

[Explanation of symbols]

 4 CD-G signal processing circuit 5 Subcode decoder 6 NTSC encoder 7 Timing control circuit 8 NTSC output terminal 9 Television format conversion circuit 12 PAL output terminal 13 Video disk video processing circuit 14 Blueback video generation circuit 15 Pulse generation circuit 21, 22, 23 switch 24 switching control circuit

Claims (3)

[Claims] 1. A disc reproducing apparatus for reproducing a disc on which video data of a non-interlaced scanning system is recorded, wherein the video data read from the disc is demodulated to generate a composite video signal conforming to a predetermined television system. A composite video signal generation circuit for generating, a television system conversion circuit for converting the composite video signal from the composite video signal generation circuit into a composite video signal conforming to another television system, and an interlace scanning system for displaying a specific video screen And a video signal generating circuit for generating a video signal, wherein the composite video signal generating circuit generates a composite video signal in synchronization with a video signal generated from the video signal generating circuit, and the video signal. It is equipped with an asynchronous mode in which a composite video signal is generated without being synchronized with the signal, and an external synchronous mode and an asynchronous mode are selectively set. A disk reproducing device characterized by being settable. 2. A first output terminal for deriving a composite video signal obtained by the composite video signal generation circuit, and a second output terminal for deriving a composite video signal obtained by the television system conversion circuit. And a pulse generation circuit for generating various pulses used in the generation of the composite video signal by the composite video signal generation circuit based on the video signal generated by the video signal generation circuit, and various pulses from the pulse generation circuit And a selection circuit for selectively supplying the composite video signal generation circuit to the composite video signal generation circuit, and various pulses from the pulse generation circuit when the composite video signal derived from the second output terminal is not used. 2. The disk reproducing apparatus according to claim 1, wherein the selection circuit is switched so as not to be supplied to the disk. 3. The video signal generation circuit is provided in a video processing circuit used for reproducing a disc on which a video signal of an interlace scanning system is recorded, and displays a monitor screen in a state other than the reproduction of the disc. 2. The disc reproducing apparatus according to claim 1, wherein a color back signal generating circuit is used.