EP0038217A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Video tape recorder with inter-channel switching circuit for extra modes of reproduction
Assignee: Panasonic Holdings Corp
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Filing: 1981-04-14
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Granted: —
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Expires: 2001-04-14
Abstract
Abstract In a video tape recorder, luminance and chrominance signals are recorded respectively by first and second transducer heads (A, A'; B, B') along separate tracks skewed to the direction of tape motion. The transducer heads are rotated in a different tape-head speed relationship during extra modes such as slow-motion or still picture reproduction from the normal tape-head speed relationship, causing the transducer heads to traverse several tracks. A switching circuit (16) is coupled to the transducer heads to selectively connect the outputs of the heads to an output circuit (23, 28) in response to a point of transition of amplitude of the output signal from the second head (B, B') to cancel unwanted signal components detected by the heads during traversal across the tracks.
Inventors
- 👤 Kunio Sekimoto
- 👤 Katsuhiko Yamamoto
- 👤 Chojuro Yamamitsu
- 👤 Kozo Kurashina
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 18:40
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/7908; H04N9/80; H04N9/82; H04N9/825; H04N9/87
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
189 words
A video tape recorder having a first and a second transducer head adapted to receive first and second signals respectively and mounted on the circumference of a rotary cylinder which is driven in a predetermined speed relation with the movement of a recording tape during recording to record said signals along alternate tracks skewed to the direction of movement of said tape, and means for driving said cylinder in a manually selectable speed relation with the movement of said tape during reproduction which differs from said predetermined speed relation thereby producing from said transducer heads unwanted signals having a waveform of rapidly varying transitions, comprising: changeover switch means having a fist terminal coupled to said first transducer head and a second terminal coupled to said second transducer head for selectively connecting the signal applied to one of said terminals to an output terminal in response to a switching control signal applied thereto; and means effective when said cylinder is driven in said manually selectable speed relation for detecting each point of the rapid transition of a single derived from said second transducer head to generate said switching control signal.
Claim 2
Dependent Claim
189 words
A video tape recorder having a first and a second transducer head adapted to receive first and second signals respectively and mounted on the circumference of a rotary cylinder which is driven in a predetermined speed relation with the movement of a recording tape during recording to record said signals along alternate tracks skewed to the direction of movement of said tape, and means for driving said cylinder in a manually selectable speed relation with the movement of said tape during reproduction which differs from said predetermined speed relation thereby producing from said transducer heads unwanted signals having a waveform of rapidly varying transitions, comprising: changeover switch means having a fist terminal coupled to said first transducer head and a second terminal coupled to said second transducer head for selectively connecting the signal applied to one of said terminals to an output terminal in response to a switching control signal applied thereto; and means effective when said cylinder is driven in said manually selectable speed relation for detecting each point of the rapid transition of a single derived from said second transducer head to generate said switching control signal.
Claim 3
Dependent Claim
53 words
A video tape recorder as claimed in claim 1, wherein said first transducer head has a greater core width than the core width of said second transducer head so that said first signal is recorded on a greater width track than the width of the track on which said second signal is recorded.
Claim 4
Dependent Claim
21 words
A video tape recorder as claimed in claim 2, wherein said first and second signals are luminance and chrominance signals, respectively.
Claim 5
Dependent Claim
81 words
A video tape recorder as claimed in claim 1, 2 or 3, wherein said second signal comprises first and second components which are recorded in the form of frequency-division multiplex on a common track, and wherein said detecting means comprises means for separating a signal reproduced by said second transducer head to recover said first and second components of different frequencies, and means for detecting the envelope of said first and second different frequency components for generating said switching control signal.
Claim 6
Dependent Claim
92 words
A video tape recorder as claimed in claim 4, wherein said first and second components of different frequencies are I and Q signals respectively, the I signal having a higher frequency than said Q signal, and wherein said means for detecting the occurrence of a minumum level of said detected envelope derived from said I signal, and bistable means responsive to the output of said minumum level detecting means and to said detected envelope derived from said Q signal, said bistable means having an output terminal connected to said changeover switch means.
Claim 7
Dependent Claim
38 words
A video tape recorder claimed in claim 5, further comprising means for demodulating said I and Q signals, and means for disabling said demodulated I and Q signals when said cylinder is driven at said manually selectable speed.
Claim 8
Dependent Claim
88 words
A video tape recorder as claimed in claime 1, 2 or 3 further comprising second changeover switch means having a first and a second terminal coupled to said first and second transducer heads respectively for selectively connecting the signal applied to one of said terminals to an output terminal in response to said switching control signal so that the signals reproduced by said first and second transducer heads are crosscoupled to the output terminals of the first and second switch means in response to said switching control signal.
References Cited (Backward Citations)
No citation records indexed.
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