Optical disk, optical disk apparatus, optical disk recording and reproduction method, and apparatus and method for recording BCA code

Abstract

A disc (1) has a burst cut area (BCA) (10) formed by a crystalline part and an amorphous part, and the disc (1) is an optical disc in which the reflectance of the crystalline part is lower than that of the amorphous part ( L-H medium). The width Wcry of the crystalline portion in the BCA(10) is less than half of the data period Wdat. Therefore, the average level of the BCA reproduction signal does not change regardless of whether the optical disc is an HL medium or an L-H medium, so that focus control and BCA code reproduction can be performed even if the circuit parameters are default values.

Description

technical field [0001] The present invention relates to an information recording medium (optical disc) having a burst cutting area (BCA), an optical disc device using BCA, an optical disc recording and reproducing method, and a device and method for recording BCA codes. Background technique [0002] As well known, as an optical disc that can record information at a high density, an optical disc having a storage capacity of 4.7 GB in a single-sided single-layer format has become commercially practical. For example, optical discs that are actually used include DVD-ROM (Digital Versatile Disc Read-Only Memory), Rewritable+RW (ECMA-300), DVD-RAM (Random Access Memory) (ECMA-330) as Read-Only Discs , and DVD-RW (rewritable) (ECMA-338). [0003] In these optical discs, an information recording layer is formed on a transparent substrate, and information is recorded and reproduced by focusing a laser beam on the information recording layer. The information recording surface of the...

AI Technical Summary

Problems solved by technology

[0010] When a conventional optical disc device is used to reproduce an optical disc having a signal polarity different from that of an H-L medium, there is a problem that the compatibility of the optical disc is reduced, information reading errors are increased, or it takes a long time to distinguish the disc.

When mixing optical discs whose signal average levels are significantly different from each other, it is necessary to expand the pulling enabling range of the focus servo circuit in order to focus the laser beam on the optical disc, which results in difficulty or cost in the design of the optical disc device. raised questions

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