Cryptography – Key management – Having particular key generator
Patent
1993-05-17
1996-12-10
Barron, Jr., Gilberto
Cryptography
Key management
Having particular key generator
380 5, 360 60, 348319, 348335, H04N 7167, H04N 592, H04N 5913
Patent
active
055839363
ABSTRACT:
Enhancements to a video anticopying process that causes an abnormally low amplitude video signal to be recorded on an illegal copy. The enhancements in one version introduce into the overscan portion of the television picture, just prior to the horizontal or vertical sync signals but in active video, a negative going waveform that appears to the television receiver or videotape recorder to be a sync signal, thereby causing an early horizontal or vertical retrace. One version provides (in the right overscan portion of the picture), a checker pattern of alternating gray and black areas which causes the TV set on which the illegal copy is played to horizontally retrace earlier than normal in selected lines with a consequential horizontal shift of the picture information on those lines. This substantially degrades picture viewability. In another version a gray pattern at the bottom overscan portion of the picture causes vertical picture instability. In another version selected horizontal sync signals are narrowed, causing irregular vertical retraces. Also provided is apparatus for removing or attenuating these enhancements from the video signal, to allow copying.
REFERENCES:
patent: 4488183 (1984-12-01), Kinjo
patent: 4631603 (1986-12-01), Ryan
patent: 4695901 (1987-09-01), Ryan
patent: 4716588 (1987-12-01), Thompson et al.
patent: 5133008 (1992-07-01), Fujita
patent: 5155767 (1992-10-01), Noller
patent: 5157510 (1992-10-01), Quan et al.
patent: 5194965 (1993-03-01), Quan et al.
Research Disclosure No. 328, Aug., 1991, Emsworth GB XP217919 "Copy Protection For Video Signals".
Elecktor Electronics, vol. 14, No. 160, Oct., 1988, Canterbury, GB pp. 44-47, XP4613, "Macrovision Decorder/Blanker".
Corcoran Jeremy J.
Knox Alistair J.
Quan Ronald
Ryan John O.
Wonfor Peter J.
Barron Jr. Gilberto
Brill Gerow D.
Macrovision Corporation
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