发明名称 |
PROTECTION OF A COMPONENT VIDEO SIGNAL |
摘要 |
A VGA (or other component video signal) output, e.g. from a computer or DVD player, is protected so it is viewable on a VGA monitor. However, if the component video signal is converted to composite video (e.g. television) the resulting television picture is of substantially degraded quality, thereby inhibiting viewing and/or copying. This protects for instance copyrighted material in the VGA format from unauthorized use. The protection involves modifying the horizontal or vertical synchronization signals in the VGA video in such a way that there is no adverse affect on a typical VGA monitor. However, most or all VGA to television converters and/or television sets and VCR's suffer from loss of synchronization, resulting in an unviewable picture. Also, methods and circuits for defeating the copy protection are provided.
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申请公布号 |
WO9900977(A1) |
申请公布日期 |
1999.01.07 |
申请号 |
WO1998US12558 |
申请日期 |
1998.06.16 |
申请人 |
MACROVISION CORPORATION |
发明人 |
RYAN, JOHN, O.;QUAN, RONALD;KUROWSKI, KORDIAN, J. |
分类号 |
H04N5/91;H04N5/913;H04N5/92;(IPC1-7):H04N5/913;H04N7/171 |
主分类号 |
H04N5/91 |
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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