APPARATUS FOR GENERATING MARKING USABLE FOR COPYGUARD OF OPTICAL DISC, METHOD FOR FORMING LASER MARKING OF OPTICAL DISC, REPRODUCING APPARATUS, OPTICAL DISC AND METHOD FOR MANUFACTURING OPTICAL DISC

摘要

PURPOSE: An apparatus for generating a marking usable for copyguard of an optical disc, a method for forming a laser marking of an optical disc, a reproducing apparatus, an optical disc and a method for manufacturing an optical disc are provided to improve copyguard capability. CONSTITUTION: A disc is formed by inputting software(816,820). Marking is performed to the disc for preventing pirated edition(819a). Accurate position information of a mark is read to obtain position information as disc physical characteristic information(819b). The physical characteristic information is enciphered(819c). A signal obtained by PWM(Pulse Width Modulation) modulating the cipher is recorded on the disc by a laser as a bar-code signal(819d).