Disc-shaped optical recording medium and reproduction limit method thereof

Abstract

Provided are a disc-type optical recording medium and a reproduction limitation method for the disc-type optical recording medium, which are used to prevent illegal copying and the like, so as to realize the protection of digital content. A type of CD that can be reproduced on an ordinary audio CD player but cannot be read at high speed on a CD-ROM drive attached to a computer. The CD (10) has a clamping hole (14) formed at a position offset from the center position of the disc base (12) relative to the outer diameter of the disc base (12), so that the center of rotation provided by the relative clamping hole is offset The center of gravity of the disc base (12) is formed at a predetermined amount of positions. In addition, a coating material (16) as an eccentric weight is applied to the label side (10A) of the CD (10). Since the center of gravity and the center of rotation of the CD (10) are eccentric to each other, the stability of the rotation can be maintained during low-speed rotation without being affected by the eccentricity. However, at high-speed rotation, the stability of the rotation cannot be maintained, resulting in reproduction failure. Therefore, illegal copying and the like are prevented to realize protection of digital content.

Description

technical field [0001] The present invention relates to a disc-type optical recording medium applicable to various systems, such as CD (Compact Disc) and DVD (Digital Laser Video Disc), and to a reproduction limitation method for the disc-type optical recording medium. Background technique [0002] For example, CDs dedicated to music information have become widespread these days, and various kinds of music can be reproduced with CD players dedicated to CDs. In this case, digital information of a CD reproduced by a CD player is actually converted into an analog sound signal, and output to a speaker, a tape recorder, or the like. [0003] Meanwhile, CD-ROMs or CD-Rs for data processing mainly used by computer peripherals, which are used to store or record data processed by computers through various disk drives, have been provided. In this case, the information of the CD-ROM or CD-R is handled as digital information. [0004] By the way, with the popularization of various com...

AI Technical Summary

Problems solved by technology

[0005] In addition, although it is convenient to extract the music information of the CD as digital data without loss in this way, the problem of copyright protection has arisen and become a major social problem

Specifically, with the promotion of network broadband communication not only in distributing or selling CD-Rs containing exactly the same content as the original CD to unrelated people but also in distributing favorite music contained in CDs to unrelated people through the network , the problem becomes more serious

Images