JPS63282981A - Method for performing disk - Google Patents

Abstract

PURPOSE:To rapidly shift to a video performing action by moving the information detecting point of a pick-up immediately to the lead-in area of a video area and starting the reading when the performance only at the video area of a compound disk is designated. CONSTITUTION:When the performance only at the video area is designated by an operating part 36, a CPU immediately accelerates a spindle motor 2 toward the maximum specified rotation speed of a video area, simultaneously, drives and rotates a carriage motor 5 at a high speed and moves a pick-up 3 toward the video area at a high speed. When it is judged that the beam spot of the pick-up 3 arrives at the lead-in area of the video area from the detecting output of a position detector 35, the TOC of the area is read. When an address designation is executed,the spot of the pick-up 3 is moved to the designation track, and when the designation is not executed, a program area is performed in succssion to the video lead-in area.

Description

[Detailed description of the invention] Lost light 1 The present invention relates to a disc playing method.

As an information recording disk (hereinafter simply referred to as a disk) on which digital signals are recorded, a small digital audio disk with a diameter of about 12 cm called a compact disk (CD) is known. However, recently, PCM (Pulse
In addition to the Code Modulation) signal, FM
Discs (hereinafter referred to as composite discs) on which a modulated video signal and a PCM signal are multiplexed are being commercialized.

As shown in FIG. 3, this composite disc has a first area 1a on the inner circumferential side (hereinafter referred to as CD area) in which audio information is recorded as PCM, for example, and an FM area.
Information is recorded in a second area (hereinafter referred to as a video area) lb in which a modulated video signal and a PCM audio signal are multiplexed. The video signal contains higher frequency components than the PCM 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. Therefore, video area 1b
When recording signals to the CD area 1a, it is necessary to make the rotational speed of the disc higher than when recording signals to the CD area 1a, and as a result, naturally, during performance, the disc rotation speed is higher than that in the video area 1b compared to the CD area 1a. must be played at a high rotational speed. As shown in FIG. 5, the rotation speed is several hundred rpm in the CD area 1a, while in the video area 1b it is around 2,000 rpm at the innermost circumference of the area.
m, the rotational speed is extremely high, reaching over 1,000 rpm at the outermost circumference.

Further, as shown in FIG. 5, the composite disc has a lead-in area for each of the CD area and video area, and each lead-in area has a TOC (TOC) indicating the program content of each area. TableOfContent
ts) is recorded, and the TOC of the audio lead-in area also includes identification data indicating whether the disc has a video area or not.

When playing this composite disc, if only the video area is specified, first read the TOC information in the glue-in area of the CD area to confirm that the disc has a video area, and then set the information detection point of the pickup. A commonly considered performance method is to move the player toward the lead-in area of the video area and start reading recorded information from that area.

However, when such a performance method is adopted, it is necessary to go through the procedure of reading the recorded information in the lead-in area of the CD area, so it takes that much time to shift to the performance operation in the video area. Become.

The present invention has been made in view of the above-mentioned points, and provides a disc performance that allows for a faster transition to the performance operation when performance of only the video area is specified when playing a composite disc. The purpose is to provide a method.

The playing method according to the present invention includes the following steps when playing a composite disc:
If performance in only the video area is specified, the information detection point of the pickup is immediately moved toward the lead-in area of the video area, and reading of recorded information is started from the lead-in area.

fire once -1 Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a configuration diagram showing an example of a disc playing device to which a playing method according to the present invention is applied. In the figure, a disk 1 is rotationally driven by a spindle motor 2, and recorded information is read by an optical pickup 3. 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 for biasing the information detection point (information detection point) in the disk radial direction with respect to the recording track is built in. The pickup 3 has a slider 4 that is movable in the radial direction of the disk.
The slider 4 is linearly driven by a transmission mechanism 6 consisting of a combination of a rack and a pinion, for example, using a slider motor 5 as a drive source. pickup 3
The read RF (high frequency) signal output from the RF amplifier 7
through the video information demodulation system 8 and digital information demodulation system 9
is supplied to

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 the horizontal (1-(> synchronization signal), vertical (V) synchronization signal, and control data included in the video signal. The time axis correction circuit 11, for example,
The delay amount of the element is controlled by the time axis control circuit 1.
The configuration is such that time axis correction is performed by changing the time axis according to the control signal from 3. Time axis control circuit 13
For example, the oscillation output of the crystal oscillator (VC, It is configured to output a control signal according to the phase difference between the synchronization signal and the color burst signal, and its specific configuration is described in Japanese Patent Laid-Open No. 56-10218.
This is shown in Publication No. 2, etc.

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 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 stored in the D/A (
The signal is converted into an analog signal by a digital/analog converter 22, and is supplied to 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. Select the video signal that has passed through 18 and output it to video output terminal 2.
Supply to 4.

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 on the a side when playing the CD area, and on the b side when playing the video area, and is switched in response to a switching command issued from the system controller 21.

In the case of a composite disc, the CD
The disc rotation 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, if the digital signal is directly superimposed on 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. The signal level is the same, but the EFM signal is recorded with the signal level suppressed by several tens of outputs relative to the video carrier (No. 4
(see figure). Therefore, even if the same EFM signal is played, the frequency characteristics and amplitude will be different when playing in the CD area and when playing in the video area. Therefore, by switching the signal processing system of the reproduced EFM signal between the CD area and the video area, the demodulation system can be changed. The aim is to share the information.

That is, when playing the CD area, the reproduced RF signal is
The EFM signal is an M signal, and the frequency characteristics of this EFM signal are compensated by equalizer circuits 26-9 to 26-9 having predetermined equalizing characteristics, and further amplified by an amplifier 27 with a predetermined gain. On the other hand, when playing in the video area,
EFM included in the reproduced RF signal together with the FM video signal
Only the signal is extracted by an EFM extraction circuit 28 consisting of an LPF or the like, the frequency characteristics are compensated by an equalizer circuit 29 which has equalizing characteristics different from those of the equalizer circuit 26, and an amplifier 3 having a larger gain than the amplifier 27.
By being amplified by 0, it is output as an EFM signal with frequency characteristics and amplitude equivalent to those when playing in the CD region.

Incidentally, when playing 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 parity -10- included in the signal, and a frame synchronization signal is detected from the EFM signal. The demodulation/correction circuit 31 demodulates and
The corrected digital audio signal 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 341.34R.

A detection signal is generated near the travel path of the pickup 3 in the disk radial direction 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. The system controller 21 receives a horizontal synchronization signal, a vertical synchronization signal, and control data from the separation circuit 12, a frame synchronization signal from the demodulation/correction circuit 31, and an operation unit 36 that determines whether the disc to be played is a compact disc or a composite disc. and mode specification information indicating whether the performance area during performance of the composite disc is only the CD area, only the video area, or a double-head area, etc. In the system controller 1 to roller 21, the CPU processes input signals according to a program stored in advance in the ROM, and drives the selection switch 15, 25, memory control circuit 19, and spindle motor 2 (not shown). ), controls the drive circuit 37 that drives the slider motor, the display section 38, etc., and also performs demodulation and demodulation during disc play.
The frame synchronization signal from the correction circuit 31 is monitored.

Note that the rotation control of the spindle motor 2 during performance of a composite disc is performed by the demodulation/correction circuit 31 of the digital information demodulation system 9, regardless of the performance area, based on the frequency and phase error between the frame synchronization signal in the EFM signal and the reference clock. This is done based on the spindle error signal generated from the spindle error signal.

Next, the steps of the performance method according to the present invention executed by the CPU constituting the system controller 21 when a composite disc is played by the disc performance apparatus having such a configuration will be described with reference to the flowchart shown in FIG. It is assumed that the disc has already been set at the performance position, and the procedure will be described when only the video area is designated to be played.

First, when performance of only the video area is specified on the operation unit 36 (step S1), the CPU immediately accelerates the spindle motor 2 toward the maximum prescribed rotational speed for the video area based on this mode specification information (step S2).
At the same time, the carriage motor 5 is driven to rotate at high speed to move the pickup 3 toward the video area at high speed (step S3). Thereafter, when it is determined that the beam spot (-information detection point) of the pickup 3 has reached the lead-in area of the video area based on the detection output of the position detector 35 (step S4), the TO in the lead-in area
The operation is then shifted to reading the C information (step S5).

When it is determined that the TOC information in the video lead-in area has been read (step S6), it is determined whether a desired address has been specified in advance for performance (step S7).
), if an address is specified, the beam spot of the pickup 3 is moved to the track of the specified address (step S8), and then the program area is played (step S9); if no address is specified, the beam spot of the pickup 3 is moved to the track of the specified address (step S8). The process moves directly to step S9, and the program area is played following the video lead-in area. When it is determined that the performance of the program area has ended (step 510), the series of performance operations of only the video area is ended. Note that when only the video area is specified, special playback such as search, scan, program play, repeat, etc. only within the video area is possible.

Even if only the video area was specified to be played,
If the disc being played is a disc that does not have a video area, reading the TOC information in step S5 is impossible, so when it is determined that the TOC information cannot be read in step S6, for example, the playing operation is stopped. do. In addition, instead of stopping the performance operation, the beam spot of the pickup 3 is moved to the lead-in area of the CD area, and after reading the TOC information in that area, the C
It may be possible to shift to the performance operation in area D, or, in a performance device capable of playing a plurality of discs, to shift to the performance operation of another disc.

As explained above, according to the disc playing method according to the present invention, when playing only the video area is specified when playing a composite disc, the information detection point of the pickup is immediately set to the lead-in of the video area. Since the recording information is moved toward the lead-in area and reading of the recorded information is started from the lead-in area, it is possible to move to the performance operation in the video area more quickly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a disc playing device to which the disc playing method according to the present invention is applied, FIG. 2 is a flow chart showing the procedure of the disc playing method according to the present invention executed by a CPU, and FIG. 3 is a composite FIG. 4 is a diagram showing the frequency spectrum of a signal recorded in the video area of the composite disc; FIG. 5 is a diagram showing the division of the information recording area on the composite disc. . Explanation of symbols of main parts 1...Disk 2...Spindle motor 3...Optical pickup 5...Slider 7-ta-8...・Video information demodulation system 9... Audio information demodulation system 11... Time axis correction circuit 15.25... Selection switch 18... Video memory

Claims (1)

[Claims] A method for playing an information recording disc having a first area in which only digital signals are recorded and a second area in which frequency modulated video signals and digital signals are multiplex recorded, the method comprising: If performance is specified only in the area, the information detection point of the pickup is immediately moved toward the lead-in area of the second area, and reading of recorded information is started from the lead-in area. How to play a disc.