发明名称 |
Digital compact disc player security system reproducing method and apparatus |
摘要 |
A security system for preventing disc players from being used with unauthorized software is disclosed. The security code is stored through modulating an offset of the physical position of a plurality of data bits from a nominal track position. A two part optical read head provides an RF signal corresponding to the presence of a physical offset modulation. The RF signal is present when there is a physical offset of the data bits defining a first logical state and the absence of the RF signal defines a second logical state. A digital security code is encoded and decoded in this manner. A system for encoding a security code through modulating the physical offset of a plurality of data bits from a nominal track position is also disclosed.
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申请公布号 |
US6304971(B1) |
申请公布日期 |
2001.10.16 |
申请号 |
US19990374931 |
申请日期 |
1999.08.16 |
申请人 |
KUTARAGI KEN;HIRANO TETSUYA |
发明人 |
KUTARAGI KEN;HIRANO TETSUYA |
分类号 |
G06F12/14;G06F1/00;G06F3/06;G06F21/24;G11B7/00;G11B7/004;G11B7/007;G11B7/013;G11B7/24;G11B7/26;G11B20/00;G11B20/10;G11B20/12;(IPC1-7):G06F12/14 |
主分类号 |
G06F12/14 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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