Method and apparatus for preventing the copying of a video program
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Mar 6, 1990
Issued Date -
N/A
app pub date -
Nov 1, 1988
filing date -
Aug 11, 1986
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A video signal is modified so that a television receiver will still provide a normal color picture but which a video tape recorder will detect and prohibit its being recorded. A plurality of ordered pairs of pseudo-sync and positive pulses are added to the video signal vertical blanking interval following the normal sync pulse. A disabiling circuit associated with a recorder detects the modified signal. This detection may be by comparing the voltage differential between the pseudo-sync pulse tip and the positive pulse relative to the normal voltage differential between the sync pulse tip and the back porch of the blanking interval. Alternatively, the modified signal can be detected by identifying the pulse frequency of the signal in the blanking interval. A high frequency is indicative of the presence of the modified signal. Detection is also shown by peak-detecting the video signal and sampling this peak-detected signal during the vertical blanking period. A control signal is produced, when the modified signal is present, which disables the recording device. If no modified signal is detected, the recording device is enabled.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully