JPS6387648A - Information reproducing system for recording disk reproducing device - Google Patents

Abstract

PURPOSE:To reproduce a composite disk in accordance with the intention of a program software presenting marker by immediately reproducing the video area of a disk in preference to the other areas if this disk to be reproduced is discriminated as the composite disk. CONSTITUTION:When the composite disk is set to the reproducing position and a start command is issued from an operation part 36, a slider motor 5 is driven to move a pickup 3 to the innermost peripheral position of the disk. Index code information recorded on an audio read-in area is read after the pickup 3 is focused, and a spindle motor 2 is immediately accelerated to a maximum prescribed rotative speed on the video area if the set disk is discriminated as the composite disk. Simultaneously, the slider motor 5 is rotated and driven at a high speed to quickly move the pickup 3 to the outer peripheral part of the disk. Thereafter, the reproducing operation is started when it is detected by a position detector 35 that the pickup 3 reaches the video area.

Description

TECHNICAL FIELD The present invention relates to an information reproducing method, and more particularly to an information reproducing method in an apparatus for reproducing a recording disk (hereinafter simply referred to as a disk) on which digital signals are recorded.

BACKGROUND ART The disc on which digital signals are recorded is called a compact disc (CD) and has a diameter of approximately 12 cm.
A small-sized digital audio disc is known, but recently, PCM with the same size as the disc
In addition to pulse code modulation (Pulse Code Modulation) signals, discs (hereinafter referred to as composite discs) on which FM-modulated video signals and PCM signals are recorded in a superimposed manner are being developed.

In this composite disc, for example, a first area on the inner circumference side in which audio information is recorded as P'CM, and an area on the outer circumference side from a predetermined radius position, in which FM-modulated video signals are recorded. Information is recorded in a second area in which the PCM audio signal is superimposed and recorded.

By the way, when playing a compact disc, first read the index code recorded in the lead-in area and read the index code recorded in the lead-in area. It is common to play back sequentially in the direction. Therefore, if it is possible to play both compact discs and composite discs on the same playback device, the composite disc will also be played from the first area on the inner circumference side unless there is a specific command from the operator. It is considered that

However, in the case of a composite disc, the program with both video and audio information recorded in the second area is the main program of the disc, and the program with only audio information recorded in the first area is the auxiliary program. It is generally considered to be provided as a program, and to record related programs as double-headed program software. Therefore, when playing a composite disc, if there is no particular instruction from the operator,
As mentioned above, if the auxiliary programs in the first area are always played back, there is a concern that the main program intended by the program provider may not be viewed, or even if it is viewed, it will only be viewed at the end. It turns out to be a problem. In particular, when compact discs and composite discs are mixed in an autochanger or the like, the playback device becomes inconvenient to use.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and provides an information reproducing method in a recording disc reproducing device that enables reproduction in accordance with the intentions of a program software provider of a composite disc when reproducing a composite disc. The purpose is to

The information reproducing method according to the present invention is implemented in a reproducing apparatus capable of reproducing both compact discs and composite discs.
When playing a disc, if it is determined that the disc to be played is a composite disc, the second area of the disc is immediately played with priority over other areas.

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

The composite disc 1 according to the present invention shown in FIG. It has a second area (hereinafter referred to as video area) 1b in which a video signal and a PCM audio signal are 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 FM signal. For this reason,
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. As shown in FIG. 3, the rotational speed is several hundred rpm in the CD area 1a.
pm, whereas in the video area 1b, the rotational speed is extremely high, 2,000-plus rpm at the innermost periphery of the area and 1,000-plus 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. A first and second index code group corresponding to each area is recorded by repeating the index code indicating the start and end time, etc., and the index code in the audio lead-in area indicates that the disc is composite. Type information indicating whether or not it is a disc is also included.

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

In FIG. 4, a disk 1 is rotationally driven by a spindle motor 2, and recorded information is transferred to an optical pickup 3.
Read by The pickup 3 includes an optical system including a laser diode, an objective lens, a photodetector, etc., a focus actuator that drives the objective lens in the optical axis direction with respect to the information recording surface of the disk 1, and a beam spot emitted from the pickup 3. A tracking actuator and the like that bias the information detection point (information detection point) in the disk radial direction with respect to the recording track are built in. The pickup 3 is mounted on a slider 4 that is movable in the radial direction of the disk, and the slider 4 is linearly driven by a transmission mechanism 6 that uses a slider motor 5 as a drive source and is made up of a combination of a rack and pinion, for example. Reading RF (high frequency) output from pickup 3
The signal 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 from the RF amplifier 7
The signal is demodulated into a video signal by a double signal 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. The time axis correction circuit 11 includes, for example, a CCD (Cha
It is configured to perform time axis correction by changing the amount of delay of the element in accordance with a control signal from the time axis control circuit 13. The time axis control circuit 13 is
For example, the oscillation output of a crystal oscillator (VCXO) 14 that oscillates in synchronization with a horizontal synchronization signal and its frequency-divided output separated and extracted by the separation circuit 14, and the horizontal synchronization signal and color in the video signal that have passed through the time axis correction circuit 11. It is configured to output a control signal according to the phase difference with the burst signal, and its specific configuration is shown in Japanese Patent Application Laid-Open No. 56-102182.

The time axis corrected video signal is supplied to a selection switch 15 and is also supplied to an A/D (analog/digital) converter 17 via an LPF (low pass filter) 16. 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 supplied to a video memory 18 consisting of a RAM (random access memory) or the like.

The video memory 18 used has a storage capacity capable of storing at least one field's worth of video information. 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 controls the video memory in response to a write enable signal W output from a system controller 21, which will be described later. The configuration is such that control is performed to rewrite the contents of each of the 18 addresses.

The data read from the video memory 18 is
It is converted into an analog signal by a (digital/analog) converter 22, and becomes an extraction input of the selection switch 15 via an 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 is switched to the b side in response to a switching command from the system controller 21 to output the video memory. 18 is selected and supplied to a video output terminal 24.

On the other hand, the digital information demodulation system 9 is provided with a selection switch 25 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 Fig. 3, <CD
The disc rotational speed is extremely different between the area and the video area, and the PCM audio signal is, for example, E F M (
Eight to Fourteen Modulat
ion) signal, and in the video domain, the digital signal is directly FM modulated during recording.
``If superimposed on the signal, the EFM signal will have a negative effect on the low frequency components of the FM video signal.
Although the degree of modulation is the same, the EFM signal is recorded with a signal level suppressed by several tens of degrees relative to the video carrier (see FIG. 2). Therefore, even with the same EFM signal, C
Since the frequency characteristics and amplitude are different when reproducing the D area and when reproducing the video area, the demodulation system is shared by switching the signal processing system of the reproduced EFM signal between the CD area and the video area. It is.

That is, when reproducing the CD area, the reproduced RF signal is EF
The EFM signal has its frequency characteristics compensated by an equalizer circuit 26 having predetermined equalizing characteristics, and is further amplified by an amplifier 27 with a predetermined gain. On the other hand, in the case of video area playback, FM is included in the playback RF signal.
Only the EFM signal included with the video signal is extracted by an EFM extraction circuit 28 consisting of an LPF or the like, and the frequency characteristic is compensated by an equalizer circuit 29 which has equalizing characteristics different from that of the equalizer circuit 26. By being amplified by the amplifier 30 having a gain, it is output as an EFM signal with frequency characteristics and amplitude equivalent to those during CD region reproduction.

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

The reproduced EFM signal selected by the selection switch 25 is demodulated and
The signal is supplied to the correction circuit 31. This demodulation/correction circuit 31 demodulates the EFM signal and writes it into a memory such as a RAM, controls the RAM based on the clock from the reference clock generator 32, exchanges data, and performs deinterleaving and the data. Error correction is performed using the parity contained in the data, and control data is further detected. 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 left and right channel audio output terminals 34L and 34R. be done.

Near the travel path of the pickup 3 in the disk radial direction, a detection signal is generated by detecting that the beam spot emitted from the pickup 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 is composed of a microcomputer including a CPU (central processing circuit), ROM (read only memory), RAM, and the like.

This system controller 21 receives the horizontal synchronization signal, vertical synchronization signal and control data from the separation circuit 12, as well as demodulation and control data.
Control data from the correction circuit 31, disc designation information indicating whether the disc to be played back is a compact disc or a composite disc from the operation unit 36, whether the playback area when playing a composite disc is only a CD area or only a video area, or Mode designation information indicating whether the area is both areas or the like is supplied. In this system controller 21, the CPU processes input signals according to a program stored in advance in the ROM,
It controls various parts such as the selection switches 15 and 25, the memory control circuit 19, a drive circuit (not shown) for driving the spindle motor 2, a drive circuit 37 for driving the slider motor, and a display section 38.

Next, the procedure for reproducing a composite disc executed by the CPU constituting the system controller 21 in the disc reproducing apparatus having such a configuration will be described 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 to move the pickup 3 to the innermost position of the disc. It is moved to a circumferential position (step Sl). When a detection switch (not shown) detects that the pickup 3 has reached the innermost circumference position, the pickup 3 is focused, and then the index code information recorded in the audio lead-in area on the innermost circumference of the disc is Reading is performed (step S2), and then it is determined whether or not the set disc is a composite disc based on this read information (step S3). If it is a compact disc, the mode directly shifts to the CD play mode (step S4), and the playback operation continues unless there is a command such as program selection. Furthermore, since the playback operation in CD play mode is well known,
The explanation will be omitted here.

If it is determined in step S3 that the disc is a composite disc, 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 move the pickup 3 to the disc. It is moved at high speed in the outer circumferential direction (step S6).

Thereafter, when it is detected that the pickup 3 has reached the video area based on the detection signal from the position detector 35 (step S7), the reproduction operation of the video area is started (step S8). During reproduction of this video area, control is performed so that at least one field (or one frame) of predetermined video information obtained from the disc is written into the video memory 18. The video information to be written is
It may be the first information of the video area, and may also be specified in advance by address designation on the operation unit 36, for example.

When it is detected in step S9 that the reproduction of the video area has ended, the spindle motor 2 is decelerated toward the maximum specified rotational speed in the CD area (step 510);
At the same time, the slider motor 5 is driven to rotate at high speed to move the pickup 3 to the innermost position of the disk at high speed (step 511).

When it is detected by the detection output of the detection switch mentioned above that the pickup 3 has reached the innermost position of the disc (
Step 512), the reproduction operation of the CD area is started (Step 813). At this time, the video information demodulation system 8
The selection switch 15 is switched to the b side, the video information written in the video memory 18 is selected during video area reproduction, and is output as a video, and still images are reproduced during the CD area reproduction period. When it is detected that the playback of the CD area has ended by reading the audio readout information (step 514), if there is no particular operation command, the slider motor 5 is driven to move the pickup 3.
is moved to the home position (step 515), and the disc is ejected by a loading mechanism (not shown) (step 516), thereby completing the series of playback operations.

In the above embodiment, the video information obtained from the disc during playback of the video area is written to the video memory 18 for one field or one frame, and
Although still images are played back based on the video information while playing back the area, it is also possible to omit the signal processing system of the video memory 18 and simply display a specific color when playing back the CD area. .

As described in detail, according to the present invention, in a playback device capable of playing both compact discs and composite discs, when it is determined that the disc to be played is a composite disc when playing a disc, by immediately giving priority to playing the video area of the disc,
Since the theme program software on the composite disc can always be played back, the composite disc can be played back in accordance with the intentions of the program software provider.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the division of the recording area of a composite disc, Figure 2
The figure shows the frequency spectrum of the signal recorded in the video area of the composite disc, Figure 3 shows the division of the information recording area on the composite disc, and Figure 4 shows the frequency spectrum of the signal recorded in the video area of the composite disc. FIG. 5 is a block diagram showing the configuration of a disc reproducing apparatus according to the present invention, and FIG. 5 is a flowchart showing the procedure executed by the CPU when reproducing a composite disc. Explanation of symbols of main parts 1... Disk 2... Spindle motor 18 = 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

Claims (2)

[Claims] (1) A first disk having, on at least one side, a first area where only a predetermined digital signal is recorded and a second area where a frequency modulated video signal and a predetermined digital signal are recorded in a superimposed manner. and a second disc on which a predetermined digital signal is recorded over the entire area. If it is determined based on this read information that the type of disc to be played is the first disc, the information detection point of the pickup is immediately moved toward the second area, and the information detection point of the pickup is moved toward the second area. An information reproduction method characterized by giving priority to reproduction over other information. (2) The information reproducing apparatus according to claim 1, wherein after the reproduction of the second area is finished, the reproduction of the first area automatically takes over.