CD device, CD recording method and compact discs

Abstract

An optical disk apparatus for recording information of copyright on an optical disk where desired data are recorded by repetition of pits or marks. The apparatus comprises a recording means for recording the copyright information by irradiating a laser beam onto the optical disk in such a manner as to repeatedly form, in a predetermined area of the optical disk, local regions which cause greater changes in the return-light receiving result as compared with the pits or marks. On the optical disk, the existence ratio of the local regions for recording the copyright information is set to be less than 0.3 in the circumferential direction of the disk. In a reproduction mode, the copyright information recorded like a bar code for example can be exactly reproduced with certainty.

Description

technical field [0001] The present invention relates to an optical disc device, an optical disc access method, and an optical disc, and more particularly to those suitable for application to a disc recording / reproducing device, an optical disc accessing method, and an optical disc, and the disc recording / reproducing device is for Designed for Mini Disc (MD), Compact Disc (CD), Digital Video Disc (DVD), etc. The present invention is conceived in such a way that when copyright information is recorded by repeatedly forming partial regions that cause a greater change in the return light receiving result than pits or marks, the existence of such partial regions in the circumferential direction of the optical disk The existence ratio is set to be less than 0.3 to ensure accurate playback of copyright information recorded like, for example, barcodes. Background of the invention [0002] Recently, it has been noticed that a compact disc device conventionall...

AI Technical Summary

Problems solved by technology

[0007] In this bar code recording process based on the known conventional method, there is a problem that the operation of the optical pickup is unstable, causing the copyright protection information to not be reproduced accurately.

When accessing is performed in the area where copyright protection information is recorded in the above-mentioned manner, the period of time during which a sufficient amount of return light cannot be received in the optical disc device becomes relatively long, so that an error in performing appropriate focus control occurs

If such proper focus control is difficult to achieve, then the correct playback of copyright protected information in optical disc devices is also difficult to achieve

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