JPH02152031A - Disk - Google Patents

Abstract

PURPOSE:To prevent the wrong recognition of the index information by crosstalks by providing the use inhibit special tracks to the boundary positions of respective groups and preformatting the signals specific to the special tracks and flag information. CONSTITUTION:The signals of the use inhibit special tracks 8-1, 8-2 for are included in the reproduction signals when the use inhibit special track 8-1 is reproduced; however, the signal from the special track 8-2 is smaller than the signal from the special track 8-1 and, therefore, the signal 9 specific to the special track preformatted in the special track 8-1 is given priority and the wrong recognition of the index information of the special track 8-2 is prevented. The wrong recognition of the index information of the special track 8-1 is prevented similarly in the special track 8-2 as well. The flag information indicating the special tracks 8 is added to the index information in order to prevent the erroneous recording of the data in the special tracks 8 and to identify these tracks from use enable tracks 7.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a disk used in an optical disk recording/reproducing device or the like.

Conventional Technology Chikasaka Computer processing of large amounts of information such as image information is progressing. Optical disk devices are used as devices for recording and reproducing such large amounts of information.

Conventionally, in such an optical disk device, information is recorded or reproduced using a disk on which information is recorded in a spiral manner and an optical head that is moved linearly in the radial direction of the disk by a linear motor.

By the way, in such an optical disk device, stable recording/reproduction is required.1. In addition, to shorten access time, the rotation speed constant force type (CAV method) where the rotation speed of the disk is constant.
ConstantLAngular Velocit
Recording and playback are performed using the y method).

In the CAV system, the number of sectors per track is constant on both the inner and outer tracks. Therefore, since the recording pits on the outer periphery become larger, the recording density per unit track length decreases, making it unsuitable for increasing density.

In addition, for high-density variable recording on optical discs, the constant linear velocity method (CLV method) slows down the rotational speed of the optical disc as it moves from the inner circumference to the outer circumference of the optical disk to keep the relative speed between the optical head and the optical disk constant. : Con5t
There is a method of recording and reproducing using the ant Linear Velocity method). This CLV type optical disk has the advantage of a large recording capacity per disk, but it also requires a long access time because it is necessary to change the rotation speed of the rotation morph according to the radial position. There were drawbacks.

Therefore, by keeping the rotational speed of the optical disk constant and switching the frequency of demodulation modulation according to the access position,
Recording/playback method (MCAV method: HoduIa)
Le Con5tant Angular Veloc
ity method] has been put into practical use. In this method, the area from the inner circumference to the outer circumference of the disk is divided into multiple groups in the radial direction, and within each group, the number of sectors is constant, and between groups, the number of sectors per track is one or more. Increase or decrease.

In this way, in the MCAV method, recording pits are grouped so that the size of the recording pits is approximately constant on the inner and outer circumferences of the disk.

Problems to be Solved by the Invention In optical disk devices, cross-tock occurs due to the tilt or off-track of the optical head;
Information about adjacent tracks may be misrecognized. M.C.
For discs such as AV discs in which the number of sectors differs between disc groups, the physical positions of the index information of sectors of tracks of adjacent groups differ in tracks at the boundaries where groups are switched. However, there is a problem in that the index information of adjacent tracks is mistakenly recognized due to crosstalk.

In view of the above problems, the present invention provides index information tA due to crosstalk at group boundaries with a minimum configuration.
The purpose of this invention is to provide a disc that can prevent V2.

Means for Solving the Problems In order to solve the above problems, in the disc of the present invention, a prohibited special track is provided at the boundary position of each group of the disc, and a special track is provided in the data recording area of this prohibited special track. A track-specific signal is preformed, and flag information indicating that the track is a prohibited special track is preformatted in the index information area.

Effect of the Invention With the above-mentioned means, the present invention can prevent a signal unique to a special track from erroneously recognizing the index information of an adjacent track even if crosstalk occurs.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a disc, such as an optical disc, according to the invention. The optical disk 1 is made of a circular substrate made of glass or plastic, for example, and the surface of the substrate is coated with a metal film layer, and tracks 2 in the form of caulking grooves are formed in a spiral shape on the surface. This track 2 is divided into a plurality of sectors 3, and each sector 3 is composed of an index information area 4 and a data recording area 5.In the index information area 4, index information is preformatted.

This optical disc l is divided into a plurality of groups 6 in the radial direction from the outer circumference to the inner circumference, and each group 6-
1.6-λ6-Y... has two prohibited special tracks 8-1.8-2 at the boundary positions between the usable track 7 and each group 6.

These prohibited special tracks 8 are preformatted with a signal 9 unique to the special track.

This signal 9 is the focus 1 which is preformed at equal intervals.
Consists of 0. The interval between pits 10 is made smaller than that of index information area 4. This focus 10 prevents erroneous recognition of index information of adjacent tracks due to crosstalk. The use prohibition signal 9 immediately before the index information area 4 makes the interval between the focus points 10 smaller so that the index information can be reliably recognized.

FIG. 2 shows the structure of index information for each track. In FIG. 2, 11 is a synchronization signal when reproducing index information, 12 is a signal indicating that it is an index information area, 13 is flag information indicating that it is a prohibited special track, and 14 is index information 15 is a redundant part. In this way, by having the flag information 13 indicating that the track is a prohibited special track in the index information area, the usable track 7 and the prohibited special track 8 can be distinguished. In other words, the contents of the flag information 13 (binary number "o o" means usable track 7; binary number ``°01'''' means prohibited special track 8-L on the outer circumferential side in the radial direction; binary number "10" means inner track). The prohibited special track 8-2 on the circumferential side is indicated, and when a prohibited special track is further added toward the inner circumference, the content of the flag information is set to a binary number 11''.

FIG. 3 shows an optical disk recording and reproducing apparatus using this disk. In Fig. 3, 1 is an optical disk, and 16 is a disk motor that rotates the optical disk at a constant speed.
17 is a motor drive circuit that drives the disk motor 16;
18 is an optical head for recording and reproducing data on the optical disk l; 19 is a linear morph drive circuit that moves the optical head 18 to access a specified track; 20 is a near-morph drive circuit that drives the linear morph 19;
1 is a laser drive circuit that drives the semiconductor laser that is the light source of the optical head 18; 22 is a head amplifier that amplifies the signal extracted from the optical head in one day; 23 is the optical head 18;
Control the focus and tracking of 1 Focus/
Trunking control circuit, 24 is a modulation circuit that modulates the write information signal, 25 is a demodulation circuit that demodulates the signal taken out by the head amplifier 22, 26 is an index information read that reproduces and reads index information from the signal of the head amplifier 22. 27 is a clock generation circuit 528 which generates a recording/reproduction processing frequency for each group, a controller circuit composed of a CPU that controls the above-mentioned components, and 29 is a data input/output circuit which controls recording/reproduction data. be.

The operation of the optical disk device configured in this manner will be described below. First, the optical disc 1 is rotated at a constant speed by the disc motor 16, and then the optical head 18 is tracked by the focus/trunking circuit 23 with a focus system as n and follows the track of the optical disc 1. Further, the optical head 18 accesses a predetermined track by a linear motor 19 driven by a linear motor drive circuit 20. The controller circuit 28 reads the current track address where the optical head 18 is located using the index information reading circuit 26, sets the difference from the target track address in the linear motor drive circuit 20, and moves the linear motor 19 to search for the target track. . Also,
Does the controller circuit 28 have a sequential focus pull-in system? It performs sequence system i3W for trace tracking, starts control of the disk motor 16 and laser, and sets the processing frequency of the current group.

Next, recording and reproducing data on the optical disc l will be explained. Write data is generated from the data input/output circuit 29 in synchronization with the recording processing frequency generated from the clock generation circuit 27. The modulation circuit 26 modulates the write data into a form that is actually recorded on the optical disk 1.The laser drive circuit 21 uses this modulation signal to modulate the optical head 18.
The optical output of the laser is controlled to record data on the optical disc l. During reproduction, the head amplifier 22 outputs and amplifies the signal recorded on the optical disk 1 using the optical head 1. The ijj modulation circuit 25 demodulates the reproduction signal obtained by the hesodon amplifier 22 in synchronization with the reproduction processing frequency generated by the clock generation circuit 27. This reproduction signal also includes index information in addition to the recorded data information, and the index information reading circuit 26 reads the track address from the index information in the reproduction signal.

In the optical disc 1 shown in FIG. 1, the signal reproduced from the head amplifier 22 shown in FIG. 3 includes information about a track that is on-track in the IL and information about a track adjacent to that track due to crosstalk. When the prohibited special track 8-1 shown in FIG. 1 is played back, the playback signal output from the head amplifier 22 shown in FIG.
2 signals are included. However, since the signal 9 unique to the special track is preformed in the data recording area of the prohibited special track, the prohibited special track 8
There is no possibility of misrecognizing the index information of ~2. In other words, the signal from the prohibited special track 8-2 due to crosstalk is sufficiently smaller (about 30 dB) than the signal from the prohibited special track 8-1, which is on-track, so it is on-track as a playback signal. Priority is given to the special track-specific signal 9 preformatted to the prohibited special track 8-1. As a result, the index information of the prohibited special track 8-2 will not be erroneously recognized. Similarly, the index information of the prohibited special track 8-1 will not be mistakenly recognized in the prohibited special track 8-2.

In order to avoid accidentally recording data on the prohibited special track 8 and to distinguish between the prohibited special track 8 and the usable track 7, the index information includes flag information indicating that the prohibited special track 8 is a prohibited special track 8. 13 was added. Furthermore, information indicating the order of a plurality of prohibited special tracks is also added to the flag information 13, and this is used when searching from the prohibited special tracks.

As described in detail, according to the present invention, with a minimum configuration,
It is possible to obtain a disc that can prevent erroneous recognition of index information due to crosstalk at group boundaries.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of the configuration of a disk according to an embodiment of the present invention. FIG. l... ・Optical disc, 2... ・Track, 3.
...Sector 4...Index information area, 6.
...Group, 7... Usable tran 9 8... Special tran 9 prohibited to use

Claims (5)

[Claims] (1) It has a spiral or concentric track, and this track is divided into a plurality of groups in the radial direction, and the number of sectors per track increases or decreases in each group depending on the position in the radial direction. A disc characterized in that one or more special tracks that cannot be recorded are provided at the boundary positions between the groups of the first half. (2) The flag information for distinguishing between the index information at the beginning of each sector of the special track and the index information at the beginning of each sector of the ordinary recordable track is preformatted. disc. (3) The disc according to claim 2, wherein information indicating the order of the plurality of special tracks is added to the flag information. (4) The disk according to claim 1, wherein a signal unique to the special track is preformatted in the data recording area after the index information area of each sector of the special track. (5) The disk according to claim 4, characterized in that the signal unique to the special track is preformatted with a signal that sequentially generates one pulse at intervals equal to or smaller than the time interval of the index information area.