Invention Grant
US07957253B2 Multiple recording layers optical disc having physical position information of pre-recording marks 失效
具有预记录标记物理位置信息的多记录层光盘

Multiple recording layers optical disc having physical position information of pre-recording marks
Abstract:
An optical disc (101) to and from which information can be reproduced and recorded by laser irradiation is provided with a first recording layer (102) and a second recording layer (104). The first recording layer (102) has a first recording mark (103) that is formed in a spiral track. The second recording layer (104) is behind or in front of the read-side surface of the first recording layer (102), and neither a wobble track nor a track for reproducing or recording information by laser irradiation is formed on the second recording layer (104). On the second recording layer (104) are formed, by laser irradiation, a second recording mark (105) that is positioned in the radial direction of the optical disc according to a predetermined position on the spiral track of the first recording layer. The optical disc (101) ensures the secrecy of the copyright protected information that is recorded thereto and the copyright protection function of the optical disc (101), and is resistant against illegal copying.
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