Video recording and/or reproducing apparatus with edit control circuit
First Claim
1. A control circuit to control recording of magnetic signals on a longitudinal control track of a video tape, wherein said video tape contains segments of video information recorded in video tracks thereon and said control track contains alternating regions of first and second polarities having a first duty ratio, said regions of first and second polarities being adapted to generate control pulses supplied as inputs to phase-locked loop circuits for controlling playback of said video information;
- said control circuit comprising;
a stationary control head for recording said alternate regions of said control signal in said control track;
edit signal means coupled to said control head for changing the duty ratio of said control signal to a second duty ratio; and
selecting means coupled to said edit signal means for selectively actuating the latter so that selected segments of said video signal are accompanied by said control signal at said second duty ratio to identify such segments as video information to be edited;
said edit signal means including switching means having a fixed terminal coupled to said control head, first and second switched terminals and a control input, means coupled to the first switched terminal of said switching means to generate control pulses in response to movement of said control track past said control head, first timing circuit means for supplying to the second switched terminal of said switching means a DC signal for a predetermined duration following occurrences of said control pulses during actuation of said selecting means, and second timing circuit means for supplying to the control input of said switching means a switching signal of a predetermined duration in response to occurrences of said control pulses during actuation of said selecting means.
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Accused Products
Abstract
A control circuit for video tape recording and/or playback apparatus is coupled to a stationary control head for selectively changing the duty ratio of the control signal that accompanies the recorded video signal and is the same signal that is used to control the servo operation of head drum and capstan motors of the apparatus. Normally, the duty ratio of the control signal is 50%, but the control circuit permits an operator to selectively alter the duty ratio, for example, to 30%, to indicate that the accompanying segment of the recorded video signal is to be edited out, that is, skipped over when the tape is played back. A duty-ratio detector coupled to the control head discriminates the duty ratio of the reproduced control signal, and a system controller automatically changes the mode of the apparatus to advance at fast-forward past those portions of the video signal accompanied by a 30%-duty-ratio control signal.
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Citations
5 Claims
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1. A control circuit to control recording of magnetic signals on a longitudinal control track of a video tape, wherein said video tape contains segments of video information recorded in video tracks thereon and said control track contains alternating regions of first and second polarities having a first duty ratio, said regions of first and second polarities being adapted to generate control pulses supplied as inputs to phase-locked loop circuits for controlling playback of said video information;
- said control circuit comprising;
a stationary control head for recording said alternate regions of said control signal in said control track; edit signal means coupled to said control head for changing the duty ratio of said control signal to a second duty ratio; and selecting means coupled to said edit signal means for selectively actuating the latter so that selected segments of said video signal are accompanied by said control signal at said second duty ratio to identify such segments as video information to be edited; said edit signal means including switching means having a fixed terminal coupled to said control head, first and second switched terminals and a control input, means coupled to the first switched terminal of said switching means to generate control pulses in response to movement of said control track past said control head, first timing circuit means for supplying to the second switched terminal of said switching means a DC signal for a predetermined duration following occurrences of said control pulses during actuation of said selecting means, and second timing circuit means for supplying to the control input of said switching means a switching signal of a predetermined duration in response to occurrences of said control pulses during actuation of said selecting means. - View Dependent Claims (2, 3, 4, 5)
- said control circuit comprising;
Specification