JPH0373067B2 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to a recording disk reproducing apparatus, and more particularly to an apparatus capable of reproducing a recording disk on which digitized signals are recorded (hereinafter simply referred to as a disk).

Background Art A small digital audio disk with a diameter of approximately 12 cm called a compact disk (CD) is known as a disk on which digital signals are recorded. , PCM (Pulse Code Modulation)
Besides the signal, FM modulated video signal and PCM
A disk (hereinafter referred to as
(referred to as composite disks) are being developed.

In the case of this composite disc, for example, the first disk on the inner circumference side, where the audio information is recorded as PCM,
and a second area on the outer circumferential side of the predetermined radial position where an FM modulated video signal and a PCM audio signal are superimposed and recorded.
Information will be recorded in separate areas.

By the way, in the case of a composite disc, a program with both video information and audio information recorded in the second area is the main program of the disc, and a program with only audio information recorded in the first area is auxiliary. Generally speaking, it is considered to be provided as a standard program, and to include related program software for both areas.

However, since only audio information is recorded in the first area, video information cannot be obtained when playing back that area, making a TV monitor unnecessary, but when playing back the second area, Since this is necessary, it is necessary to keep it in the on state at all times, and it is necessary to display some kind of image on the television monitor for viewing when the first area is reproduced.

Summary of the invention The present invention has been made in view of the above points, and
It is an object of the present invention to provide a recording disc reproducing device capable of displaying an image related to a first area of a composite disc even when reproducing the first area.

A recording disk playback device according to the present invention is a device capable of playing back a composite disk, and is equipped with a video memory capable of recording video information for at least one field, and is equipped with a video memory capable of recording video information for at least one field, and is read from the disk when playing back a second area. At least one field worth of video information is written in the video memory, and when at least the first area is reproduced, the stored information in the video memory is read out and output as a video.

Embodiment Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

Composite disk 1 according to the present invention shown in FIG.
For example, the first area 1a on the inner circumferential side (hereinafter referred to as CD area) in which audio information is recorded as PCM, and the FM-modulated video signal and
It has a second area (hereinafter referred to as a video area) 1b in which a PCM audio signal is recorded in a superimposed manner. PCM for video signal
The signal contains higher frequency components than the signal, and the frequency spectrum of the signal recorded in the video area 1b is as shown in FIG. In the figure, the component indicated by A is a PCM signal, and the component indicated by B is a video signal.
It is an FM signal. Therefore, when recording signals to the video area 1b, it is necessary to increase the rotational speed of the disc compared to when recording to the CD area 1a.
It is necessary to reproduce the disc at a higher rotational speed in the video area 1b than in the video area 1b. The rotation speed is as shown in Figure 3, CD area 1
In the video area 1b, the rotation speed is several hundred rpm, whereas in the video area 1b, the rotation speed is extremely high, being over 2,000 rpm at the innermost periphery of the area and over 1,000 rpm at the outermost periphery.

A lead-in area is provided at the beginning of each of the CD area 1a and the video area 1b, and each lead-in area contains an index code related to the recorded content of each area, for example, each small part constituting each area. The first and second index code groups are recorded corresponding to each area by repeating the index code indicating the start and end time, etc. of the disc. It also includes type information indicating whether or not the disk is a composite disk.

Next, the configuration of a recording disc reproducing apparatus capable of reproducing such a composite disc will be explained.

In FIG. 4, a disk 1 is rotationally driven by a spindle motor 2, and recorded information is read by an optical pickup 3. This pick-up 3 includes a laser diode, an objective lens,
A beam spot (information detection point) emitted from an optical system including a photodetector, a focus actuator that drives an objective lens in the optical axis direction of the information recording surface of the disk 1, and a pickup 3 is used as a recording track. On the other hand, a tracking actuator and the like for biasing the disk in the radial direction is built in. The pick-up 3 is mounted on a slider 4 which is movable in the radial direction of the disk, and the slider 4 is linearly driven by a transmission mechanism 6 consisting of a combination of a rack and pinion, for example, using a slider motor 5 as a drive source. A read RF (high frequency) signal output from the pickup 3 is supplied to a video information demodulation system 8 and a digital information demodulation system 9 via an RF amplifier 7.

In the video information demodulation system 8, the RF signal from the RF amplifier 7 is demodulated into a video signal by a demodulation circuit 10, and then supplied to a time base correction circuit 11 and a separation circuit 12. The separation circuit 12 separates and extracts a horizontal H synchronization signal, a vertical V synchronization signal, and control data contained in the video signal. Time axis correction circuit 1
1 is, for example, CCD (Charge Coupled, Device)
It is comprised of variable delay elements such as, for example, and is configured to perform time axis correction by changing the delay amount of the element in accordance with a control signal from the time axis control circuit 13. The time axis control circuit 13 is connected to the separation circuit 14.
For example, the phase difference between the oscillation output of the crystal oscillator VCXO 14 that oscillates in synchronization with the horizontal synchronization signal and its frequency-divided output separated and extracted, and the horizontal synchronization signal and color burst signal in the video signal that has passed through the time axis correction circuit 11. It has a configuration that outputs a control signal according to the
- Shown in Publication No. 102182, etc.

Select switch 1 for the time axis corrected video signal.
A/D (analog/digital) via LPF (low pass filter) 16
It is supplied to a converter 17. In the A/D converter 17, the video signal is sampled at a predetermined period, and the obtained sample values are sequentially converted into digital data. The output data of this A/D converter 17 is stored in RAM (random access memory).
are supplied to a video memory 18 consisting of, etc. As the video memory 18, one having a storage capacity capable of recording at least one field's worth of video information is used. Address control and mode control of the video memory 18 are performed by a memory control circuit 19. The memory control circuit 19 sequentially reads the data written in each address of the video memory 18 using the clock from the reference clock generation circuit 20, and responds to a write enable signal w output from the system controller 21, which will be described later. The configuration is such that control is performed to rewrite the contents of each address in the video memory 18. The data read from the video memory 18 is
It is converted into an analog signal by an A (digital/analog) converter 22, and becomes another input to the selection switch 15 via the LPF 23. The selection switch 15 is normally located on the a side, and supplies the video signal directly supplied from the time axis correction circuit 11 to the video output terminal 24, and switches to the b side in response to a switching command from the system controller 21, whereby the video memory is switched to the b side. 18 is selected and supplied to a video output terminal 24.

On the other hand, the digital information demodulation system 9 includes a selection switch 2 that switches depending on the area to be played (CD area and video area) when playing a composite disc.
This switch 25 is located on the a side when reproducing the CD area and on the b side when reproducing the video area, and the switching is performed in response to a switching command issued from the system controller 21. In the case of a composite disc, as explained in Figure 3, the rotation speed of the disc is extremely different between the CD area and the video area, and the PCM audio signal is, for example, EFM (Eight to Fourteen Modulation).
In the video domain, if the digital signal is directly added to the FM-modulated video signal during recording, the EFM signal will have a negative effect on the low-frequency components of the FM video signal, so the modulation degree is Although it is equivalent, the EFM signal is recorded with the signal level suppressed by several tens of dB compared to the video carrier (see Figure 2). Therefore, even if the same EFM signal is used, the frequency characteristics and amplitude will be different when playing the CD area and when playing the video area, so by switching the signal processing system of the reproduced EFM signal between the CD area and the video area, The aim is to make the double-tone system common.

That is, when reproducing the CD area, the reproduced RF signal is an EFM signal, and the frequency characteristics of this EFM signal are compensated by an equalizer circuit 26 having predetermined equalizing characteristics, and further amplified by an amplifier 27 with a predetermined gain. On the other hand, in the case of video area reproduction, only the EFM signal included together with the F video signal in the reproduced RF signal is extracted by the EFM extraction circuit 28 consisting of an LPF, etc., and has equalization jig characteristics different from that of the equalizer circuit 26. The frequency characteristics are compensated by the equalizer circuit 29, and the signal is amplified by the amplifier 30, which has a gain greater than that of the amplifier 27, so that it is output as an EFM signal with the same frequency characteristics and amplitude as when playing the CD area. be.

Incidentally, when playing back a compact disc, the selection switch 25 is always in a state where the a side is selected.

The reproduced EFM signal selected by the selection switch 25 is supplied to a demodulation/correction circuit 31. This demodulation
The correction circuit 31 demodulates the EFM signal and
In addition to writing to memory such as RAM, the RAM is controlled based on the clock from the reference clock generator 32, data is exchanged, de-interleaved, and error correction is performed using the parity contained in the data. Detects control data. The digital audio signal demodulated and corrected by the demodulation/correction circuit 31 is processed by an audio signal processing circuit 33 consisting of a D/A converter, a deglitcher circuit, etc., and then supplied to audio output terminals 34L and 34R of the left and right channels. be done.

Near the movement path of the pick-up 3 in the disk radial direction, a detection signal is generated by detecting that the beam spot emitted from the pick-up 3 has arrived at a position corresponding to the vicinity of the boundary between the CD area and the video area on the composite disk. A position detector 35 is provided. By generating this detection signal, it is possible to detect that the pickup 3 has reached the video area. As the position detector 35, one having a well-known configuration such as an optical sensor can be used.
A detection signal output from the position detector 35 is supplied to the system controller 21.

The system controller 21 includes a CPU (central processing circuit), ROM (read-only memory), and RAM.
It is composed of a microcomputer consisting of, etc. This system controller 21 includes a horizontal synchronizing signal, a vertical synchronizing signal, and control data from the separation circuit 12, control data from the demodulation/correction circuit 31, and an operation unit 36 indicating whether the disc to be reproduced is a compact disc or a composite disc. Disc specification information, playback area when playing a composite disc
Mode designation information indicating whether only the CD area, only the video area, or both areas is provided is supplied. In this system controller 21, the CPU is ROM
A drive circuit (not shown) that processes input signals according to a program stored in advance in the drive circuit and drives the selection switches 15 and 25, the memory control circuit 19, the spindle motor 2, and the slider motor. 37, controls various parts such as the display section 38.

Next, in the disk playback device having such a configuration, the CPU constituting the system controller 21
The procedure executed when reproducing a composite disc will be explained with reference to the flowchart shown in FIG.

It is assumed that the composite disc has already been set at the playback position, and in this state, when a start command is issued from the operation unit 36, the slider motor 5 is driven via the motor drive circuit 37, thereby moving the pickup 3 to the disc. Move it to the innermost position (step S1). When a detection switch (not shown) detects that the pickup 3 has reached the innermost position, the pickup 3 is focused, and then the index code information recorded in the audio lead-in area on the innermost disk is read (step S2), and then it is determined whether or not the set disk is a composite disk based on this read information (step S3). If the disc is a compact disc, the CD play mode (step S4) is entered, and the playback operation continues unless there is a specific command such as program selection. Note that since the playback operation in the CD play mode is well known, the explanation will be omitted here.

If it is determined in step S3 that the disk is a composite disk, the spindle motor 2 is immediately accelerated toward the maximum specified rotational speed in the video area (step S5), and at the same time, the slider motor 5 is driven to rotate at high speed to drive the pick-up 3. The disk is moved in the outer peripheral direction at high speed (step S6). Thereafter, when it is detected by the detection signal from the position detector 35 that the pickup 3 has reached the video area (step S7), the reproduction operation of the video area is started (step S8). During playback of this video area, at least one
Control is performed to write a field's worth (or one frame's worth) of predetermined video information into the video memory 18. This video information to be written may be the first information in the video area, or may be specified in advance by address designation on the operation unit 36, for example.

When it is detected in step S9 that the playback of the video area has ended, the spindle motor 2 is activated.
The slider motor 5 is decelerated toward the maximum specified rotation speed in the CD region (step S10), and at the same time
is rotated at high speed to move the pickup 3 to the innermost position of the disk at high speed (step S11).
When it is detected that the pickup 3 has reached the innermost position of the disk by the detection output of the detection switch mentioned above (step S12), the reproduction operation of the CD area is started (step S13). At this time, at the same time, the selection switch 15 in the video information demodulation system 8
is switched to the b side, and the video information written in the video memory 18 is selected and output as video when the video area is played back, and still images are played back during the playback period of the CD area. When it is detected that the playback of the CD area has ended by reading the audio readout information (step S14), if there is no particular operation command, the slider motor 5 is driven to move the pickup 3 to the home position (step S14). Step S15), and then eject the disk by the loading mechanism (not shown) (step S15).
S16), the series of playback operations ends.

In the above embodiment, if the set disk is determined to be a video disk, the video area is immediately played back, and after the playback of the area is finished,
However, when starting playback from the CD area, a portion of the video area is first played, and the video information obtained at this time is stored in the video memory 18. ,
Thereafter, it is also possible to provide a still image based on the information stored in the video memory 18 at the same time as the CD area is played back.

Furthermore, the playback of still images is not limited to only when playing back the CD area; for example, the playback of still images based on the memory in the video memory 18 is performed during periods when the playback image may be disturbed, such as during jumps in the video area. It is also possible to perform the following.

Effects of the Invention As explained above, the storage disk playback device according to the present invention includes a video memory capable of storing at least one field of video information, and the storage disk playback device according to the present invention includes a video memory capable of storing at least one field of video information, and at least one field read from the disk when playing back a video area. Write video information for at least 1 minute to the video memory, and at least
When playing back the area, the information stored in the video memory is read out and output as a video, so images related to this can also be displayed when playing back the CD area.

[Brief explanation of drawings]

Figure 1 is a diagram showing the division of the recording area of the composite disc, Figure 2 is a diagram showing the frequency spectrum of the signal recorded in the video area of the composite disc, and Figure 3 is a diagram showing the frequency spectrum of the signal recorded in the video area of the composite disc.
The figure is a diagram showing the division of information recording areas on a composite disc, Figure 4 is a block diagram showing the configuration of a recording disc playback device according to the present invention, and Figure 5 is a CPU
2 is a flowchart showing the procedure executed by the system when reproducing a composite disc. Explanation of symbols of main parts 1...disk, 2...
...Spindle motor, 3...Optical pickup, 5...Slider motor, 8...Video information demodulation system, 9...Audio information demodulation system, 11...
Time axis correction circuit, 15, 25...selection switch,
18...Video memory, 21...System controller.

Claims (1)

[Claims] 1. A playable disc having, on at least one side, a first area in which only a predetermined digital signal is recorded and a second area in which a frequency modulated video signal and a predetermined digital signal are recorded in a superimposed manner. A disc playback device, comprising: a video memory capable of storing at least one field of video information; and selection means for selecting information stored in the video memory and outputting the video when playing at least the first area; at least one read from the disk during playback of the second area;
A recording disk characterized in that it is provided with a control means for writing video information for a field into the video memory, and at least when reproducing the first area, reads out the information stored in the video memory and controls the output to be a video output. playback device.