# US 4,393,417 A · Tracking system

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,393,417 A
- Document ID: US4393417A
- Status: Granted
- Kind: A
- Application number: 06/205,599
- Filed: 1980-11-10
- Granted: 1983-07-12
- Earliest claimed: 1979-06-04
- Assignees: Matsushita Electric Industrial Co., Ltd.
- Inventors: Masaaki Kobayashi; Akihiro Takeuchi; Kiyoji Fujisawa
- Web page: https://patentgrep.com/patent/US4393417A

## CPC

- G11B 5/588: by controlling the position of the rotating heads (by controlling the speed of the record carrier G11B15/467; by controlling speed of the heads G11B15/473; {by moving the transducing part of the head relative to the headwheel, in the direction of the scanning movement G11B15/1841})
- G11B 15/1808: {Driving of both record carrier and head (G11B15/467 takes precedence; mounting of head G11B5/52)}
- 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)

## Abstract

A tracking system including positionable elements, rotary video heads mounted on the positionable elements, a control head, a frequency generator attached to a capstan motor, and a displacing pattern generator. The displacing pattern generator includes counters which count the pulses from the frequency generator. The pattern generator is reset by control signals reproduced by the control head, a still pattern generator, and an adding means which adds the output signal from the counters and the output signal from the still pattern generator. The output signal of the displacing pattern generator is amplified and applied to the positionable element. As result, the video head mounted on the positionable element can properly trace on a recorded video track at a normal tape speed or at a different tape speed.

## Claims

### Claim 1

A tracking system for video recorders/reproducers employing a record medium having tracks for recording video signals and for recording control signals which are representative of the record position of said video signals, said system comprising:
a transducing means for reproducing video signals recorded along said track on said record medium;
a positionable means having said transducing means mounted at a location thereon, said positionable means being movable at said location for displacing the position of said transducing means;
a control signal reproducing means for reproducing said control signals recorded along at least one of said tracks on said record medium;
a means for dividing the interval of said control signals, said dividing means generating sub-control signals which are representative of the transported length of said record medium;
a rotating phase detector for detecting the rotating phase of said transducing means;
an operational means for generating a displacement pattern signal which is representative of the location of said video track recorded on said record medium with respect to said transducing means by using the output of said control signal reproducing means, said sub-control signals, and the output of said rotating phase detector; and
a means for supplying said displacement pattern signal to said positionable means, whereby said transducing means is capable of tracking properly on said recorded video track regardless of the transporting speed of said record medium.

### Claim 2 (depends on 1)

A tracking system as claimed in claim 1, wherein said dividing means comprises a rotary disk which rotates in correspondence with thr transporting of said record medium and a pulse generator for generating pulse signals in proportion to the rotational angle of said rotary disk, said pulse signals used for generating said sub-control signals.

### Claim 3 (depends on 1)

A tracking system as claimed in claim 1, wherein said control signal reproducing means comprises a magnetic head which responds to magnetic flux.

### Claim 4 (depends on 1, 2, 3)

A tracking system as claimed in claims 1, 2 or 3, wherein said operational means comprises: a still pattern generator, reset by said output of said rotating phase detector, for generating a still pattern signal whose amplitude is equal to zero at the beginning of a scanning by said transducing means and whose amplitude corresponds to one track pitch of said video track at the end of said scanning by said transducing means; a counter for counting said sub-control signals and for generating bias signals during a still mode of operation of said system; and an adder for adding an output of said still pattern generator and the output of said bias counter and for generating said displacement pattern signal.

### Claim 5 (depends on 4)

A tracking system as claimed in claim 4, wherein said operational means further comprises a timing circuit and at least one additional counter operatively connected to said bias counter for delaying the operation of the means for supplying said displacement pattern signal to said positionable means such that said displacement pattern signal fed to said positionable means is delayed.