# US 4,395,738 A · Helical scan tape recording and/or replay apparatus

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- Number: US 4,395,738 A
- Document ID: US4395738A
- Status: Granted
- Kind: A
- Application number: 06/210,788
- Filed: 1980-11-26
- Granted: 1983-07-26
- Earliest claimed: 1980-11-26
- Assignees: RCA Corporation
- Inventors: Lee V. Hedlund; Donald G. Herzog
- Web page: https://patentgrep.com/patent/US4395738A

## CPC

- G11B 27/323: {Time code signal, e.g. on a cue track as SMPTE- or EBU-time code}
- G11B 5/0086: {using cyclically driven heads providing segmented tracks}
- G11B 20/10527: {Audio or video recording; Data buffering arrangements (G11B20/12 - G11B20/18 take precedence)}
- G11B 27/322: {used signal is digitally coded}
- H04N 5/926: by pulse code modulation (H04N5/919 takes precedence)
- G11B 2220/90: Tape-like record carriers
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A tape has a format of the type wherein digital video information is recorded with each frame or field disposed on a set of multiple tracks and with at least one track being intended for replay during scene search modes of operation, only the most significant bits of pixels are recorded on the search tracks.

## Claims

### Claim 1

In a record and replay system of the type wherein digital video information is recorded with each field or frame disposed on a set of multiple tracks and with only a single track being intended for replay during scene search modes, the improvement comprising:
a first memory buffer unit which directs the most significant bits and the least significant bits of pixels to separate tracks through record electronics during the record mode of operation and directs those pixel bits from the tracks of operation, said first memory buffer unit being controlled by a first memory controller and having clock and mode select signals applied thereto, said memory controller having said mode select signal applied thereto as well as clock and sync signals during the record mode of operation or sync and timing signals from said replay electronics during the normal replay mode of operation;
a second memory buffer unit which directs only the most significant bits of pixels from the tracks through scene search electronics during scene search replay modes of operation, said second memory buffer unit being controlled by a second memory controller and having sync and timing signals applied thereto from said scene search electronics; and
a multiplexer which directs pixel bits from either said first or second buffer memory units during normal replay or scene search replay respectively.