# US 5,706,268 A · Apparatus for reproducing an optical recording medium having first and second pit strings on opposite sides of each track

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

- Number: US 5,706,268 A
- Document ID: US5706268A
- Status: Granted
- Kind: A
- Application number: 08/801,556
- Filed: 1997-02-18
- Granted: 1998-01-06
- Earliest claimed: 1993-07-26
- Assignees: Sony Corporation
- Inventors: Hideyoshi Horimai
- Web page: https://patentgrep.com/patent/US5706268A

## CPC

- G11B 7/0938: {servo format, e.g. guide tracks, pilot signals}
- G11B 7/0045: Recording (G11B7/006, G11B7/0065 take precedence)
- G11B 7/24085: Pits
- G11B 7/00745: {Sectoring or header formats within a track (formats in general G11B20/12)}
- G11B 7/08505: {Methods for track change, selection or preliminary positioning by moving the head}
- G11B 7/0901: {for track following only (G11B7/0925, G11B7/094, G11B7/0941, G11B7/0943, G11B7/0945, G11B7/0946, G11B7/0948 take precedence)}
- G11B 7/263: {Preparing and using a stamper, e.g. pressing or injection molding substrates (production of optical record carriers, e.g. optical discs B29D17/005)}
- 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

There is provided an optical recording medium including a first pit string having a succession of pits and mirror surface sections, which first pit string is formed on one side of a track center as a reference, and a second pit string having pits and mirror sections, reversed in their array from the pits and the mirror surface sections of the first pit string. A laser beam is radiated onto the track center for accessing information signals represented by the pits and the mirror surface sections. There are also provided a recording device and a reproducing device for such optical recording medium.

## Claims

### Claim 1

An optical recording apparatus for forming a first pit string having a succession of pits and mirror surface sections, the first pit string being formed on one side of a track center as a reference, and a second pit string formed on an opposite side of the track center and having pits and mirror sections in an array which is the logical inverse of the pits and the mirror surface sections of the first pit string, wherein a laser beam radiated onto the track center is used to access information signals represented by the pits and the mirror surface sections, comprising:
a laser light source,
a light modulator for intensity modulation of a laser beam from said laser light source depending on input recording data,
an objective lens for converging said laser beam on said optical recording medium,
means for moving said laser beam along the radius of said optical recording medium,
means for inverting said recording data, and
control means for causing said recording data directly to said light modulator for forming one of said pit strings and for causing said recording data to be supplied via said data inverting means to said light modulator for forming the other of said pit strings.

### Claim 2

An optical recording apparatus for forming a first pit string having a succession of pits and minor surface sections, the first pit string being formed on one side of a track center as a reference, and a second pit string formed on an opposite side of the track center and having pits and mirror sections in an array which is the logical inverse of the pits and the minor surface sections of the first pit string, wherein a laser beam radiated onto the track center is used to access information signals represented by the pits and the mirror surface sections, comprising:
a laser light source,
a light modulator for intensity modulation of a laser beam from said laser light source depending on input recording data,
an objective lens for converging said laser beam on said optical master recording medium,
means for moving said laser beam along the radius of said optical master recording medium,
means for inverting said recording data, and
control means for causing said recording data directly to said light modulator for forming one of said pit strings and for causing said recording data to be supplied via said data inverting means to said light modulator for forming the other of said pit strings.