发明名称 |
Information recording media and optical disc presenting a character or a graphic pattern formed by specified pit patterns on data tracks |
摘要 |
A CD-ROM is provided with an area for forming a character/graphic pattern. The character/graphic pattern is formed in such a way that data, which generate on the CD-ROM two sorts of pit patterns having average reflectances different from each other to a perceptible extent, are respectively recorded inside and outside the character/graphic pattern. Unless an illegal copy disc is produced by duplicating the legal original disc of the CD-ROM at a very high precision, the character/graphic pattern of the copy disc is invisibly deformed by the discrepancy between the arrangements of the pit patterns of the copy disc and the original disc.
|
申请公布号 |
US5608717(A) |
申请公布日期 |
1997.03.04 |
申请号 |
US19940301889 |
申请日期 |
1994.09.07 |
申请人 |
HITACHI, LTD. |
发明人 |
ITO, TAMOTSU;BANNO, HIROSHI;KOIKE, RYUICHI;TAKEUCHI, TAKASHI |
分类号 |
G11B7/005;G11B7/007;G11B7/24;G11B7/24094;G11B20/00;G11B23/28;G11B23/34;G11B23/38;(IPC1-7):G11B7/24 |
主分类号 |
G11B7/005 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|