JPH02156423A - Optical disk medium - Google Patents

Abstract

PURPOSE:To improve track density without lowering the intensity of a tracking error signal by nearly equalizing the width of the grooves and intergrooves of the optical disk. CONSTITUTION:Either of the grooves 2 or the grooves 3 is selected by changing the polarity of the tracking error signal emitted from these grooves in case of tracing the grooves 2 or the intergrooves 3 with a converged beam. Track addresses and sector addresses are recorded by prebits 4 in a prebit region 5 on the extension line of the grooves 2 and the extension line of the intergroove 3 in a data recording region 6 and the reading thereof is possible. The grooves 2 and the intergrooves 3 are equal in width and since the information can be recorded in both, the intensity of the tracking error signal is less decreased even if the track density is increased as compared to the conventional disk medium with which recording is executed only in the intergrooves 3. The track density is thus increased.

Description

[Detailed description of the invention] [Industrial application field] TECHNICAL FIELD The present invention relates to optical disc media.

[Conventional technology]

A conventional optical disc medium is constructed by forming a recording film 7 on a substrate 1 as shown in FIG. At this time, the recording film 7 is uniformly formed on the substrate l.

This substrate l has grooves 2' at regular intervals, which serve as guides for the light beam, before forming the recording film 7 thereon. User data is recorded on the recording film 7 above the groove 3' of the data recording area 6'. At this time, holes called pre-pits 4 are formed on an extension of the grooves 3' for recording data on the substrate 1, and there are pre-pit areas 5'. This pre-pit 4
Track addresses and sector addresses are recorded.

Recording and reproduction of information on the optical disc device is performed as follows.

The focused light beam traces the groove 3', reads the pre-pits 4, and if it is a necessary track address or sector address, it records information in the subsequent data recording area 6' or records the data in the data recording area. Read the information recorded in 6'.

[Problem to be solved by the invention]

However, in such conventional optical disk media, information is recorded only on the recording film between the grooves, so in order to improve the track density, the grooves and the width between the grooves must be narrowed. At the time, the focused light beam for recording and reproducing an optical disk performs tracking by obtaining a tracking error signal from the intensity distribution of the diffracted light between the grooves, so when the width of the grooves or the gaps between the grooves becomes narrow, the diffracted light This has the disadvantage that the tracking error signal strength decreases and cannot be traced.

[Means to solve the problem]

The optical disc medium of the present invention is composed of a substrate and a recording film, and has a data recording area consisting of grooves for recording data on the substrate and tracks between the grooves, and an extension of the grooves of the data recording area and the tracks between the grooves. It is configured to have a pre-pit area in which the spatial address of the disc is recorded on a line.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional perspective view showing one embodiment of the present invention. The optical disc medium shown in FIG. 1 is composed of a substrate 1, a pre-pit area 5 and a data recording area 6 on which a recording film 7 is uniformly formed.

The data recording area 6 consists of a groove 2 and a groove gap 3 having a width comparable to that of the groove 2, and the prepit area 5 is an area including prepits 4 for recording track addresses and sector addresses.

User information is recorded on the upper recording film 7 of the groove 2 formed in the data recording area 6 and on the recording film 7 above the groove gap 3.

The operation when using the optical disc medium of the present invention on an optical disc device is as follows.

When tracing the focused beam to the groove 2 or between the grooves 3, by switching the polarity of the tracking error signal generated from the groove 2 and between the grooves 3, it is possible to trace the groove 2 or to trace the groove 2.
You can choose whether to trace groove 3. Also, the track address and sector address are in the groove 2 of the data recording area 6.
Pre-pit area 5 on the extension line of and on the extension line of groove space 3
This can be read because it is recorded in the pre-pit 4.

In this optical disk medium, since both the groove 2 and the groove gap 3 have approximately the same width, information can be recorded in both the groove 2 and the groove gap 3.

Therefore, compared to a conventional optical disk medium in which information is recorded only between the grooves 3, even if the track density is increased, the intensity of the tracking error signal decreases less, making it possible to improve the track density and improve the information recording density.

〔Effect of the invention〕

The optical disc medium of the present invention can improve the track density without reducing the intensity of the tracking error signal by making the widths between the grooves almost equal, and can record information both in the grooves and between the grooves. This has the effect of dramatically increasing information recording density.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional perspective view showing an embodiment of the present invention, and FIG. 2 is a cross-sectional perspective view showing an example of the conventional technology. 1...Substrate, 2,2'...Groove, 3,3
'...Groove gap, 4...Pre-pit, 5.
5'...Pre-pit area, 6,6'...
- Data recording area, 7... Recording film. Agent Patent Attorney Susumu Uchihara

Claims (1)

[Claims] a substrate, a data recording area having a recording film formed on the substrate and configured for recording with a groove and a groove having a width comparable to the groove forming a track; and the data recording area. What is claimed is: 1. An optical disc medium comprising: grooves; and prepit areas in which addresses of the data to be recorded and reproduced are recorded by prepits formed on extension lines of tracks between the grooves.