# US 2001/0026522 A1 · Optical pickup device

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- Number: US 2001/0026522 A1
- Document ID: US20010026522A1
- Status: Published application
- Kind: A1
- Application number: 09/788,656
- Filed: 2001-02-21
- Published: 2001-10-04
- Earliest claimed: 2000-02-21
- Assignees: Pioneer Corporation
- Inventors: Naoharu Yanagawa
- Web page: https://patentgrep.com/patent/US20010026522A1

## CPC

- G11B 7/08511: {with focus pull-in only}
- G11B 7/1376: Collimator lenses {(collimators per se G02B27/30)}
- G11B 7/13922: {passive}
- G11B 2007/0013: {for carriers having multiple discrete layers}
- G11B 2007/13727: {Compound lenses, i.e. two or more lenses co-operating to perform a function, e.g. compound objective lens including a solid immersion lens, positive and negative lenses either bonded together or with adjustable spacing}
- 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

An optical pickup device including an optical system which includes a first optical path which introduces a laser beam emitted from a light source to a recording surface of an optical disc through an objective lens and a second optical path which introduces the laser beam reflected on the recording surface of the optical disc to an optical detector through the objective lens, and an optical element which is disposed at least in the first optical path such that the optical element is movable in the optical axis direction of the laser beam.

## Claims

### Claim 1

An optical pickup device comprising:
an optical system which includes a first optical path which introduces a laser beam emitted from a light source to a recording surface of an optical disc through an objective lens and a second optical path which introduces the laser beam reflected on the recording surface of the optical disc to an optical detector through the objective lens, and
an optical element which is disposed at least in the first optical path such that said optical element is movable in an optical axis direction of the laser beam.

### Claim 2 (depends on 1)

An optical pickup device according to claim 1, wherein said optical pickup device includes a driver for moving said optical element such that a spherical aberration can be reduced in said optical system.

### Claim 3 (depends on 2)

An optical pickup device according to claim 2, wherein said driver adjusts a position of said optical element such that an output signal level of said optical detector becomes a maximum value.

### Claim 4 (depends on 1)

An optical pickup device according to claim 1, wherein said optical element is a collimator lens.

### Claim 5 (depends on 4)

An optical pickup device according to claim 4, wherein said optical disc includes a plurality of recording layers, and the position of said collimator lens is adjusted in the optical axis direction of the laser beam for every reading or writing of a recording surface of each of the plurality of recording layers.