Video signal recording system
AssigneeSony Corporation
InventorHideo Honda
Life of this patent
Estimating the term…
Abstract
A video recording system is provided with a copy guard arrangement which can readily discriminate a video signal having pseudo horizontal synchronizing pulses in a portion of a vertical blanking interval, from a normal video signal, without deteriorating the quality of recorded pictures. Preferably, an analog circuitry or a microcomputer is designed to count the horizontal synchronizing pulses received during a predetermined portion of the vertical blanking interval, and to discriminate a copy-guarded video signal from an unguarded video signal in accordance with the result of the counting. In the case of the copy-guarded video signal, an inhibit signal is produced to prevent a normal recording operation.
Claims5
A video recording system comprising:
- video recording means including a recording circuit and a video record head for normally recording a video signal in a normal recording mode;
- separating means for separating horizontal synchronizing pulses of said video signal from vertical synchronizing pulses of said video signal;
- counting means for counting said horizontal synchronizing pulses fed from said separating means and producing a signal representing a count which is a total number of said horizontal synchronizing pulses received in a counting interval within a vertical blanking interval of said video signal;
- timer means connected to said counting means and receiving said vertical synchronizing pulses from said separating means and producing a counter control signal fed to said counting means to start and stop a counting operation of said counting means and define said counting interval;
- discriminating means for determining whether said count is within a predetermined range, and producing an inhibit signal to prevent a normal recording operation of said recording means when said count is within said predetermined range;
- and
- switch means interposed between said recording circuit and said video record head for disconnecting said video record head when said inhibit signal is produced by said discriminating means.
Dependencies are inferred from the claim text.