JPH01201859A - Play starting method for disk - Google Patents

Abstract

PURPOSE:To start the play for even a CD by merely changing software by repeating operations moving a pickup to an inner periphery for a prescribed time corresponding to the detection of the area boundary of a composite disk and reading a record and sub-code information until they can be read. CONSTITUTION:A processor in a system controller 11 monitors the output of a position detector 13 by a play command, and detects the area boundary by the inversion of a level. At this time, the pickup 3 is moved in a direction of the inner periphery of the disk 1 for the prescribed time, then stopped, an the lock of focusing servo, the acquirement of a frame period, and the read of the sub-code information are judged. When all of them are performed, the operation is shifted to the read of a table of content TOC or the search operation of a track NO1, and when even one of the above action is not performed, the pickup is moved to the inner side for the prescribed time additionally, and the same judgement is repeated, thereby, it is possible to start the play for even the CD with a short recording time surely without necessitating an additional position detector.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for starting a disc performance in a disc performance device, and more particularly to a method for starting a disc performance that allows multiple types of composite discs called CDVs to be played.

Background technology] Digital discs called compact discs (CDs)
Same size as the audio disc, PCM (Pul
In addition to the se Code Modulation) signal,
There is a composite disc called a CDV in which a frequency modulated video signal and a PCM signal are multiplex recorded. In the case of this composite disc, as shown in FIG. 4, there is a first area (hereinafter referred to as CD area) on the inner circumferential side in which audio information is recorded as PCM, and a video signal subjected to frequency modulation processing. The area is divided into a second area on the outer circumferential side (hereinafter referred to as a video area) in which a PCM signal and a PCM signal are multiplex recorded, and information is recorded therein.

In this composite disc, since the video signal contains higher frequency components than the PCM signal, it is necessary to increase the rotational speed of the disc when recording signals in the video area compared to when recording in the CD area. As a result, naturally, when playing a disc, it is necessary to perform the disc at a higher rotational speed in the video area than in the CD area.

In this way, when playing a composite disc, the rotational speed of the disc is extremely different between the CD area and the video area, so it is necessary to quickly change the rotational speed of the disc each time the playing area changes. For a disc player that plays a composite disc, a position detector is essential for detecting when the information reading point of the pickup has arrived at the boundary position between the CD area and the video area.

By the way, so-called compatible disc players, which can play not only composite discs and compact discs, but also video discs, which are larger in size than these discs, are rapidly becoming popular. In this compatible disc player, the lead-in area position of each disc is different for each disc, so conventionally, the area boundary position of the composite disc was located approximately midway between the respective lead-in area positions of the compact disc and video disc. Therefore, based on the position detected by the position detector, that is, the video area glue-in area position of the composite disc, the pickup is moved from this position for a predetermined time, and when the video disc starts playing, it is compacted in the direction of the disc's outer circumference. - When starting a performance in the CD area of a disc or a composite disc, it is moved toward the inner circumference of the disc, and that position is used as the performance start position. In the case of playing the CD area of a compact disc or composite disc, the start of playing is stopped if the frame synchronization signal does not lock at that position or if the subcode information cannot be read.

With this conventional disc play start method, in the case of a disc with a short recording time (for example, an 80-inch compact disc that is about to be commercialized), the play start position is closer to the outer circumference than the lead-out area position. As a result, a problem arises in that such discs cannot be played, and countermeasures are desired. Furthermore, it is difficult to accurately detect a position at which a performance can be started using time management.

Summary of the Invention The present invention has been made in view of the above-mentioned points, and it is possible to reliably start playing even a compact disc with a short recording time without changing the hardware such as adding a position detector. The purpose of the present invention is to provide a method for starting disc play that can be performed easily.

The disc play starting method according to the present invention is capable of playing multiple types of discs including composite discs, and includes a position detector that detects when an information reading point has arrived at the boundary position between the CD area and the video area of the composite disc. In the disc playing device, when a performance is started on the inner circumferential side of the disc from the boundary position, the information reading point is moved in the inner circumferential direction of the disc for a first predetermined period of time in response to the detection output of the position detector. When the recorded information at that position is read, and if frame synchronization cannot be achieved during this reading operation or subcode information cannot be read, the information reading point is further moved in the direction of the inner circumference of the disc by a second predetermined period of time and the information is read at that position. The operation of reading the recorded information in is repeated a predetermined number of times until frame synchronization is achieved or the subcode information can be read, and if frame synchronization cannot be achieved even after repeating the predetermined number of times, or the subcode information cannot be read, the performance start operation is performed. It is characterized by the discontinuation of

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

FIG. 1 is a block diagram showing an example of a disc playing device to which a disc playing starting method according to the present invention is applied;
This device is a compatible disc player that can play multiple types of discs, including composite discs, compact discs, and video discs. In the figure, a disk 1 is rotationally driven by a spindle motor 2, and recorded information is read by an optical pickup 3.

This pickup 3 includes a light source such as a laser diode,
An optical system including 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 recording track that records the light beam spot (information reading point) emitted from the pickup 3. A tracking actuator and the like are built in to bias the disc in the radial direction. The pickup 3 is mounted on a slider 4 that is movable in the radial direction of the disk.
The slider motor 5 is used as a drive source and is driven by a transmission mechanism 6 consisting of a combination of a rack and a pinion, for example. Read RF multiplied signal RF output from pickup 3
The signal is supplied via an amplifier 7 to a video information demodulation system 8 and a digital information demodulation system 9. Note that the demodulation system for demodulating the analog audio signal of the video disc is omitted in this figure.

In the video information demodulation system 8, the RF multiplied signal read from the RF amplifier 7 is demodulated into a video signal by a video demodulation circuit 80, and then supplied to a time axis correction circuit 81. The time axis correction circuit 81 is composed of, for example, a variable delay element such as a CCD, and 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 82. . The time axis control circuit 82 receives the oscillation output of a crystal oscillator (VCXO) 84 that oscillates in synchronization with the horizontal synchronization signal separated from the video signal by the synchronization separation circuit 83 and its frequency-divided output, and the time axis correction circuit 81 . It is configured to generate a control signal according to the phase difference between the horizontal synchronization signal and the color burst signal in the video signal. The video signal whose time axis has been corrected by the time axis correction circuit 81 is sent to the video output terminal 10 via the video signal processing circuit 85.
is supplied to The video signal processing circuit 85 performs various processes such as video muting to inhibit output of the video signal and character insertion.

On the other hand, the digital information demodulation system 9 is provided with a changeover switch 90 that switches depending on the area to be played (CD area and video area) when playing a composite disc, and this switch 90 is set to the a side when playing the CD area. , is on the b side when playing the video area, and the switching is performed in response to a switching command issued from the system controller 11, which will be described later. The PCM audio signal recorded in the CD area and the video area is, for example, E F M (Eight
t t.

When playing a CD area, the reproduced EFM signal passes through an equalizer circuit 91 and an amplifier 92, and then is supplied to a demodulation/correction circuit 96 via a changeover switch 90. On the other hand, when playing the video area, the EFM extraction circuit 9 uses the read RF multiplied signal.
After the reproduced EFM signal extracted in step 3 passes through an equalizer circuit 94 and an amplifier 95, it is supplied to a demodulation/correction circuit 96 via a changeover switch 90.

The demodulation/correction circuit 96 demodulates the EFM signal and outputs the R
In addition to writing to a memory such as AM (not shown), the RAM is written based on the reference clock from the reference clock generator 97.
It controls the data, exchanges data, performs de-interleaving and error correction using the parity contained in the data, and detects a frame synchronization signal from the EFM signal. The digital audio signal demodulated and corrected by the demodulation/correction circuit 96 is processed by an audio signal processing circuit 98 consisting of a D/A (digital/analog) converter, a day-glitcher, etc., and then sent to the left and right channel audio output terminals 12L, 12R, and is also supplied to a code separation circuit 99, where subcode information such as frame numbers and time codes are separated.

A position detector 13 is provided near the travel path of the pickup 3 in the disk radial direction to detect when the light beam spot emitted from the pickup 3 has arrived at the boundary position between the CD area and the video area on the composite disc. For example, the output level of this position detector 13 is inverted at the boundary position. As the position detector 13, one having a well-known configuration such as an optical sensor can be used. Position detector 13
The detection output of is supplied to the system controller 11.

The system controller 11 is composed of a microcomputer, and exchanges data with each section such as the video information demodulation system 8 and the digital information demodulation system 9 via a path line 14, and controls the changeover switch in the digital information demodulation system 9. 90, drive control of the slider motor 5 via the motor drive circuit 15, and time management based on the point in time when the detection output from the position detector 13 is generated. Performs play start control for each disc and video disc.

Next, the procedure for starting a performance executed by the processor of the system controller 11 when playing a CD area of a composite disc or a compact disc in the disc performance apparatus having such a configuration will be described with reference to the flowchart shown in FIG.

When a performance command is generated, the processor first monitors the output of the position detector 13 (step Sl).
The pickup 3 is moved from the home position toward the outer periphery of the disk until the output level is reversed, for example, from a high level to a low level (step S2). Position detector 1
When the output level of position detector 13 is reversed, this time, position detector 13
The pickup 3 is moved toward the inner circumferential direction of the disc (step S4) until the output level of is inverted from a low level to a high level (step S3). A predetermined period of time 1+ (for example,
340 m5ec) in the direction of the inner circumference of the disk (step S5), and after time t1 has elapsed, the pickup 3 is stopped (step S6). Next, the focus servo is turned on (step S7), and it is determined whether the focus servo is locked (step S8).
If it is determined in step S9 that the lock is not locked even after a certain period of time has elapsed, the system shifts to the stop mode.

When the focus servo is locked, the spindle servo is turned on (step 510), and then it is determined whether a frame synchronization signal can be stably detected, that is, whether frame synchronization has been achieved (step 511). Once frame synchronization is achieved, it is then determined whether subcode information has been read (step 512). If the subcode information can be read, the TO recorded in the lead-in area
The process moves to a read operation of C (Table Of Contents) or a search operation of track No. 1.

In this first start-up operation, if frame synchronization cannot be achieved even after a certain period of time has elapsed (step 813), or if subcode information cannot be read even after a certain period of time has elapsed (step 514), a predetermined period of time tz (e.g. , 60m5ec) further toward the inner circumference of the disk (step 515), and after time t2 has elapsed, the pickup 3 is stopped (step 516). Then, it is determined whether frame synchronization has been achieved at this stop position (step 517), and if frame synchronization has been achieved, it is subsequently determined whether subcode information has been read (step 518). If you can read the subcode information, TO
C read operation or track number.

The process moves to the search operation in step 1.

Even in this second start-up operation, frame synchronization may not be achieved even after a certain period of time has passed (step 519).
Alternatively, if the subcode information cannot be read even after a certain period of time has passed (step 520), the count value N of the internal counter is set to "2", for example, in step 521.
), followed by a predetermined time tX (for example, 20m5ec)
the pickup 3 is further moved toward the inner circumference of the disk (step 522), and after the time t3 has elapsed, the pickup 3 is moved further toward the inner circumference of the disk.
is stopped (step 523). Then, in step 8, it is determined whether or not frame synchronization has been achieved at this stop position.
24) Once frame synchronization is achieved, it is then determined whether subcode information has been read (step 525).

If the subcode information can be read, read the TOC or track number.

The process moves to the search operation in step 1.

Even in this third startup operation, frame synchronization cannot be achieved even after a certain period of time has passed (step 519).
Alternatively, if the subcode information cannot be read even after a certain period of time has passed (step 520), "1" is subtracted from the count value N of the internal counter (step 528), and then the count value N becomes N<0. If N<0 is not determined (step 529), the process returns to step S22 and the above-described operation is repeated until N<O.

In this way, the CD area of a composite disc or compact
When playing a disc, as shown in Figure 3, if frame synchronization cannot be achieved at the initial startup position or subcode information cannot be read, the pickup 3 must be moved further toward the inner circumference of the disc. By repeating the start-up operation a predetermined number of times (in this example, 5 times), you can create compact discs with a short recording time, such as 8 cmcD, by simply changing the software and without installing a new position detector. However, it means that you can definitely start up and start playing. Note that with a normal disk, it starts up at the first start-up position, so the sequence is exactly the same as the conventional one.

In the above embodiment, the management time for the second and third time is different, but the management time may be the same for the second and subsequent times, and the setting of the management time is arbitrary. In addition, the number of attempts to start up is not limited to five times, and in relation to the above management time, within a range where the slider 4 on which the pickup 3 is mounted does not go too far into the inner periphery of the disk.
It can be set to any number of times including once.

As described in detail, according to the disc play starting method according to the present invention, when playing a CD area of a composite disc or a compact disc, the information reading point is set to the first position in response to the detection output of the position detector. The information reading point is moved toward the inner circumference of the disc for a predetermined period of time to read the recorded information at that position, and if frame synchronization cannot be achieved during this reading operation or subcode information cannot be read, the information reading point is further moved for a second predetermined period of time. By repeating the operation of moving the disc toward the inner circumference and reading the recorded information at that position a predetermined number of times until frame synchronization is achieved or the subcode information can be read, hardware such as adding a new position detector can be used. Even if no changes are made, it is possible to reliably start playing even compact discs with short recording times by simply changing the software.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a disc playing device to which the disc playing starting method according to the present invention is applied, FIG. 2 is a flowchart showing the procedure of the disc playing starting method according to the present invention executed by a processor, and FIG. 4 is an explanatory diagram of the operation, and FIG. 4 is a diagram showing the division of information recording areas on the composite disc. Explanation of symbols of main parts 1...Disk 3...Pickup 8...Video information demodulation system 9...Digital information demodulation system 11...・System controller 13...
・Position detector applicant Pioneer Corporation

Claims (1)

[Claims] It is possible to play a plurality of types of discs including a composite disc having a first area in which a digital signal is recorded and a second area in which a frequency modulation signal is recorded, and the information reading point is located at the first and second areas. In a disc playing device equipped with a position detector that detects arrival at a boundary position of an area, when a performance is started on the inner circumference side of the disc from the boundary position, the information reading point is set as the detection output of the position detector. In response, the information reading point is moved toward the inner circumference of the disk for a first predetermined period of time to read the recorded information at that position, and if frame synchronization cannot be achieved during this reading operation or subcode information cannot be read, the information reading point is The operation of further moving the disk in the inner circumferential direction for a second predetermined period of time and reading the recorded information at that position is repeated a predetermined number of times until frame synchronization is achieved or the subcode information can be read, and even if the operation is repeated for the predetermined number of times. A method for starting a disc playback characterized by stopping the playback start operation if frame synchronization cannot be achieved or subcode information cannot be read.