JPH0366063A - Optical disk recording and reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical disc recording/reproducing device for recording or reproducing information on a so-called recordable or rewritable optical disc. This relates to constant rotation control of an optical disc.

[Conventional technology]

Conventionally, so-called compact discs (compact discs) on which music information etc. were recorded as digital signals using mechanical pits.
(hereinafter referred to as CD) are widely used. This CD is played back by a playback-only optical disc playback device.

The above-mentioned CD usually has a plurality of pieces of information recorded in succession, and during playback, the absolute address pre-recorded on the disc and the TO
Continuous playback, selective playback, etc. of desired information are performed by comparing the recording start absolute address value of each piece of information recorded in the C (Table Of Contents) area.

On the other hand, when recording music information on rewritable disks such as magneto-optical disks, which have been developed in recent years, or write-once optical disks that can be recorded only once, there is a difference between them and conventional CDs. It is desirable to standardize the playback method between the two and provide compatible optical disc recording and playback devices. In that case, as a rotation control method of the optical disc during recording or reproduction, the so-called constant linear velocity control (hereinafter referred to as CLV), which is implemented in CDs, is used.
near Vel.

city control) can be adopted.

By the way, when controlling the rotation of an optical disk using a CLV, for example, the rotation speed of the motor is controlled according to the rotation speed of the motor detected by a rotary encoder or the like and the radial position of the optical head detected by a position detection sensor. However, in that case, detection errors of the rotary encoder and position detection sensor will occur, so sufficiently accurate rotation control cannot be expected.

Therefore, it is conceivable to perform CLV control based on information recorded in advance on the optical disc, such as the above-mentioned absolute address. Conventionally, as an absolute address recording method, after bi-phase mark modulation of the absolute address, the guide groove of the optical disk is moved radially inward or outward depending on whether each bit is "1" or "O". bias or
Alternatively, a method in which the width of the guide groove is changed has been proposed (see Japanese Patent Laid-Open No. 39632/1983). In that case, if the frequency band of the absolute address and the frequency band of the recorded information are made different, it is possible to reproduce them separately from each other.

[Problem to be solved by the invention]

However, as mentioned above, even if information is recorded while rotating the optical disc using information such as absolute addresses previously recorded on the optical disc as a pre-recorded signal regarding position, in reality, errors in CLV control during recording may occur. etc., there is a possibility that information is recorded in a state slightly deviated from the CLV conditions. In that case, if the recorded information is music information, subtle variations will occur in the performance speed during playback, and the sound quality will be impaired. It is preferable to do so.

However, during reproduction, for example, if the optical disk enters an unrecorded area from a recorded area, there is a problem that rotation control based on reproduction information becomes impossible. Also, -dan,
Even if the quality of the reproduced signal is restored after rotation control based on reproduction information becomes impossible, there is a problem in that it takes a considerable amount of time before correct rotation control can be performed.

[Means to solve the problem]

In order to solve the above-mentioned problems, an optical disc recording and reproducing apparatus according to the present invention records or reproduces information on an optical disc on which rotation control information for controlling rotation at a constant linear velocity over the entire surface is recorded as pre-recorded information. In the optical disc recording and reproducing apparatus, an address management unit stores a recording start absolute address value obtained from the pre-recorded information at the start of the recording operation, and stores a recording end absolute address value obtained from the pre-recorded information at the end of the recording operation; ,
During recording, the pre-recorded information is used to control rotation at a constant linear velocity, and the absolute recording start and end address values stored in the address management section are recorded in a predetermined area of the optical disc, and during playback, the playback signal is While performing rotation control at a constant linear velocity based on the above, the above-mentioned recording start and recording end absolute address values are read from a predetermined area of the optical disk to the address management section and compared with the absolute address values of the area being reproduced. By this, it is determined whether it is a recorded area or an unrecorded area, and when it is determined that it is an unrecorded area, the rotation control with a constant linear velocity based on the reproduction signal is switched to the rotation control with a constant linear velocity based on the above-mentioned pre-recorded information. It is characterized in that it is provided with a control means.

[For production]

According to the above configuration, when recording in an unrecorded area of an optical disc, the linear velocity is constant (CLV) based on the pre-recorded information.
During playback, C is controlled based on the playback signal.
Since the rotation of the LV is controlled, the rotation of the CLV can be controlled appropriately depending on the purpose during recording and reproduction.

Further, during reproduction, the recording start and recording end absolute address values recorded in a predetermined area of the optical disc are read out to the address management section. The absolute address value of the current playback area is
It is compared with the read recording start and recording end absolute address values, and the control means determines whether it is a recorded area or an unrecorded area.

If the control means determines that the area is an unrecorded area, the next best measure is to use the pre-recorded signal using the position information from the CtV control based on the playback signal even during playback. Since the control is switched to CLV control, stable CLV* control can always be achieved even when the playback area approaches from a recorded area to an unrecorded area. Therefore, problems such as inability to perform rotation control during playback will not occur.

〔Example〕

An embodiment of the present invention will be described below based on FIGS. 1 to 5.

As shown in FIG. 2, on a magneto-optical disk as a rewritable optical disk, there is a TOC (T
A possible content area 1a is provided, and most of the area outside the TOCja area 1a is an information recording area ib. The information records 41b record various information such as music programs, etc.
In the OCfil area 1a, additional information regarding each piece of information recorded in the information recording area 1b, such as the recording start and end position of each piece of information, is recorded.

As shown in FIG. 3, T O in the magneto-optical disk 1
In the C61 area 1a and the information recording area 1b, spiral or concentric guide grooves 2, 2... (shown by hatching for convenience) are formed in advance at predetermined intervals in the disk radial direction. Then, after pi-phase modulation, the absolute address of each part on the disk is either "l" or "0".
”, the guide grooves 2, 2, etc. are biased toward the inside or outside of the magneto-optical disk 1 in the radial direction. This becomes recorded information.

As shown in FIG. 4, the optical disk recording and reproducing apparatus according to the present embodiment includes a spindle motor 3 that supports and rotates the above-mentioned magneto-optical disk, and a spindle motor 3 that irradiates laser light onto the magneto-optical disk during recording and reproduction. An optical disk recording/reproducing apparatus comprising an optical head 4 and a coil 5 for applying a magnetic field onto a magneto-optical disk during recording is configured to perform recording using a so-called magnetic field modulation method, and is configured to perform recording using a so-called magnetic field modulation method. It is now possible to override, recording new information over the top.

The above-mentioned optical disc recording and reproducing apparatus is equipped with an input terminal 6 for inputting information to be recorded, and the analog information input manually from the input terminal 6 is converted into a digital signal by an A/DC (analog/digital) converter 7 and then recorded. In the signal processing circuit 8, E F M (Eight Fourteen
Modulation) The signal is subjected to predetermined processing such as modulation, and then supplied to the coil driver 10.

The coil driver 10 drives the coil 5 based on the supplied signal, and at the same time, a laser beam is irradiated from the optical head 4 onto the magneto-optical disk 1, thereby recording a signal.

FIG. 5 shows the signal recording format. This format is conventionally used for CDs, and is a 24-byte music information signal with 8 bytes of parity for error correction added to each data field d, which stores music information such as song number and time information. Frame a, which is constructed by adding a subcode C indicating the frame and a frame synchronization signal S indicating the beginning of the frame, is continuously recorded. On the other hand, the subcode C in the TOC area 1a includes at least the recording end position of each piece of information, or the length from the recording start position to the recording end position, for information such as the recording start position of each piece of information in the format of a playback-only CD. This new information includes information such as size.

The regeneration system will be described below. In FIG. 4, a signal reproduced by an optical head 4 is amplified by a reproduction amplifier 11. The amplified signal is sent to a prerecorded information detection circuit 12 and a reproduction signal processing circuit 16.

The pre-recorded information detection circuit 12 is composed of, for example, a band-pass filter and a phase-locked loop, and a synchronized clock is generated by the phase-locked loop with respect to the pre-recorded information in the reproduced signal extracted by the band-pass filter. It has become. Then, the frequency of the clock synchronized with the pre-recorded information consisting of bi-phase mark modulation of the absolute address and the first reference frequency supplied from the first oscillator 13 are compared in the first comparator 14, and the difference signal is switched. The water is supplied to the container 15.

Further, this device is equipped with a pre-recorded information demodulation unit (not shown), and bi-phase marks are demodulated by this pre-recorded information demodulation unit as needed during access, and position information is further indicated by an address decoder 22 in the address management unit. decoded to an absolute address. The address management section has a structure including an address decoder 22 and a TOC memory 23. A controller 24, which will be described later, recognizes the absolute address as pre-recorded information based on the result of the address decoder 22. Note that the recording start absolute address value and the recording end absolute address value are determined by the pre-recorded information detection circuit 12 and the address decoder 22.
, controller 24, TOC memory 23, recording signal processing circuit 8, coil driver 10. and a TOC area 1a which is a predetermined area on the magneto-optical disk l via the coil 5.
It is now recorded in .

The reproduced signal processing circuit 16 performs EFM demodulation and other predetermined processing on the magneto-optical signal component in the reproduced signal supplied from the reproduced amplifier 11, and the reproduced signal is sent to a D/A (digital/analog) converter 17. and output terminal 18
It is designed to be output externally via .

Further, a synchronization signal detection pulse indicating that the frame synchronization signal has been detected in each frame in the reproduction signal is supplied from the reproduction signal processing circuit 16 to the second comparator 2o, where the synchronization signal detection pulse is supplied. The period is the second oscillator 19
The difference signal is sent to the switch 15. In addition,
When the reference frequencies of the first oscillator 13 and the second oscillator 19 are the same, a single oscillator can be used by making the first oscillator 13 and the second oscillator 19 common. Also, the first
The first reference frequency of the oscillator 13 and the second reference frequency of the second oscillator 19
If the reference frequency is an integer multiple, a single oscillator may be used and the frequency of this oscillator may be appropriately divided by a frequency divider.

The signal processed by the reproduction signal processing circuit 16 is sent to the TOC memory 23 in the address management section, and is combined with the recording start absolute address value and the recording end absolute address value recorded in advance at the time of recording, and the signal currently being reproduced by the optical herad 4. The absolute address value of the playback area currently being read is compared. The controller 24, which will be described later, is T.

Based on the contents of the C memory 23, it is determined whether the optical disc 4 is currently reproducing a recorded area or an unrecorded area.

The optical disk recording and reproducing apparatus according to the present invention includes a control means including a controller 24 and the like, and when recording a signal, this control means performs a recording operation according to the flow shown in FIG. 1(a). That is, as shown in FIG.
is switched to the first comparator 14 side and CLV@@ is performed based on the pre-recorded information (Sl), and the recording start absolute address value at this time is stored in the TOC memory 23 (S2).
), music information, etc. are recorded. When the recording of music information, etc. is completed, the recording end absolute address value at that time is stored in the TOC memory 23 (S3), and the additional information of the recording start absolute address value and the recording end absolute address value is The signal is recorded in the TOC area 1a of the magneto-optical disk 1 via the signal processing circuit 8, coil driver 10, and coil 5 (S4). On the other hand, when reproducing the signal, the switch 15 is switched to the second comparator 20 side. It is configured to perform <CLV control based on the reproduction signal.

Further, in accordance with the flow shown in FIG. 1(b), the control means controls the TOCeM area 1a, which is a predetermined area of the magneto-optical disk 1, before reproducing the signal.
and record start and end absolute address values (
The recording area information) is read out via the reproduction signal processing circuit 16 and stored in the TOC memory 23 (31), and the reproduction area obtained by reproducing the pre-recorded information recorded in advance on the magneto-optical disk l is read out. The absolute address value is the TO
It is compared with the recording area information stored in the C memory 23 (
S2), and it is determined whether the playback area is a recorded area or an unrecorded area (S3). For example, if the absolute address value of the playback area obtained by playing back the pre-recorded information is greater than or equal to the recording start absolute address value. , and is less than or equal to the recording end absolute address value, the playback area is determined to be a recording area. Along with this, the switch 15 remains connected to the second comparator 20, and rotation control is performed at a constant linear velocity based on the reproduction signal (S4).On the other hand, when the absolute address value of the reproduction area is , is smaller than the recording start absolute address value or larger than the recording end absolute address value, the area is determined to be an unrecorded area. Along with this, the switch 15 switches the second comparator 2
0 to the first comparator 14 (S5). As a result, rotation control with a constant linear velocity based on the reproduced signal is switched to rotation control with a constant linear velocity based on pre-recorded information.

Therefore, if it becomes difficult to perform <CLV control based on the playback signal, such as when approaching an unrecorded area during playback, the next best measure is to control the CLV based on pre-recorded information even during playback.
Since LvIII control (S5) is performed, CLV during playback
No problems occur that would make it impossible to control.

Although the above embodiment has been described using an example in which the absolute address on the magneto-optical disk l is bi-phase modulated, the present invention is not limited to this, and other modulation methods with limited frequency bands may be used. .

Furthermore, in the above embodiments, the magneto-optical disk 1 is used as an example of an optical disk, but the present invention can also be applied to other rewritable optical disks, such as a phase-change optical disk or a write-once optical disk. It is possible.

Further, in the above embodiment, the absolute address is recorded as pre-recorded information by biasing the guide grooves 2, 2, etc., but it may also be meandering. It may also be recorded in advance. In that case, the <CLV control may be performed based on the pre-recorded information by comparing the cycle at which the above-mentioned bits are reproduced with a predetermined reference frequency.

Further, in the above embodiment, the unrecorded area in the information recording area lb was described as an unrecorded area, but the invention can also be applied to recorded areas, unnecessary areas, unstable areas, etc.

〔Effect of the invention〕

As described above, the optical disc recording and reproducing apparatus according to the present invention is an optical disc recording and reproducing apparatus that records or reproduces information on an optical disc on which rotation control information for performing rotation control at a constant linear velocity over the entire surface is recorded as pre-recorded information. an address management unit that stores a recording start absolute address value obtained from the pre-recorded information at the start of a recording operation and stores a recording end absolute address value obtained from the pre-recorded information at the end of the recording operation; The pre-recorded information is used to perform rotation control at a constant linear velocity, and the recording start and recording end absolute address values stored in the address management unit are recorded in a predetermined area of the optical disc, and during playback, based on the playback signal. While performing rotation control at a constant linear velocity, by reading out the above recording start and recording end absolute address values from a predetermined area of the optical disk to the address management section and comparing them with the absolute address values of the area being reproduced, A control means that determines whether the area is a recorded area or an unrecorded area, and when it is determined that the area is an unrecorded area, switches from rotation control at a constant linear velocity based on the reproduction signal to rotation control at a constant linear velocity based on the pre-recorded information. This is a configuration in which

As a result, during recording, rotation control is performed at a constant linear velocity based on pre-recorded information, and during playback, rotation control is performed based on the playback signal, so that the rotation is controlled to suit the purpose during recording and playback, respectively. Control comes into play.

Additionally, during playback, if the address management unit determines that the playback area is an unrecorded area having an absolute address value other than the recording start and recording end absolute address values recorded in the predetermined area of the optical disc, the following As a good countermeasure, even during playback, we switched from <CLV control based on the playback signal to <CLV control based on a pre-recorded signal using position information, so that the playback area changes from the recorded area to the unrecorded area. Stable CLV control can be achieved at all times even when the vehicle is about to reach a certain point. Furthermore, since absolute address values are simply compared to determine whether a recorded area is a non-recorded area, there is no need to provide a new detection means, and the circuit configuration can be simplified.

[Brief explanation of drawings]

1 to 5 show one embodiment of the present invention. FIG. 1(a) is a flowchart showing the procedure for controlling the CLvI 11 during recording. FIG. 1(b) is a flowchart showing the procedure of ct and vlQ411 during reproduction. FIG. 2 is a schematic plan view of the magneto-optical disk. FIG. 3 is an enlarged plan view of the magneto-optical disk. FIG. 4 shows the countries in which the optical disk recording/reproducing device is made up of blocks. FIG. 5 is an explanatory diagram showing a signal recording format. 1 is a magneto-optical disk (optical disk), 22 is an address decoder (address management section), and 23 is a T. C memory (address management section); 24 is a controller (control means); 1st Lu (a) 2nd s (Record @ work) 'js3i! I 0 each completion)

Claims (1)

[Scope of Claims] 1. In an optical disc recording and reproducing apparatus that records or reproduces information on an optical disc on which rotation control information for performing rotation control at a constant linear velocity over the entire surface is recorded as pre-recorded information, the above-mentioned at the start of recording operation. an address management unit that stores a recording start absolute address value obtained from the pre-recorded information and also stores a recording end absolute address value obtained from the pre-recorded information at the end of the recording operation; In addition to performing rotation control at a constant speed, the recording start and recording end absolute address values stored in the address management section are recorded in a predetermined area of the optical disk, and during playback, rotation control is performed at a constant linear speed based on the playback signal. At the same time, by reading out the above-mentioned recording start and recording end absolute address values from a predetermined area of the optical disc into the address management section and comparing them with the absolute address values of the area being played back, it is possible to determine whether the area is a recorded area or an unrecorded area. and a control means for switching from rotation control at a constant linear velocity based on the reproduced signal to rotation control at a constant linear velocity based on the pre-recorded information when it is determined that the area is an unrecorded area. Characteristic optical disc recording/playback device.