Optical pickup device

• US 20040264316A1
• Filed: 06/22/2004
• Published: 12/30/2004
• Est. Priority Date: 06/25/2003
• Status: Active Grant

• Current Assignee: Funai Electric Co., Ltd.
• Original Assignee: Funai Electric Co., Ltd.
• Inventors: Matsui, Tsutomu
• Granted Patent: US 7,821,901 B2
• Time in Patent Office: Days
• US Class Current: 369/44.37
• CPC Class Codes: G11B 2007/0006 adapted for scanning different types of carrier, e.g. CD & DVD
• CPC Class Codes: G11B 7/1275 Two or more lasers having different wavelengths
• CPC Class Codes: G11B 7/131 Arrangement of detectors in a multiple array

Abstract

The optical pickup device includes a semiconductor laser for emitting laser light of 650 nm and 780 nm in wavelengths, a semiconductor laser for emitting laser light of 400 nm in wavelength, and an optical sensor which is provided in sequence with a first light receiving surface divided into four areas in a matrix manner, a second light receiving surface divided into four areas in a matrix manner, and a third light receiving surface divided at least into two areas aligned inline. Reflected light of three beams of 400 nm in wavelength and reflected light of three beams in 780 nm in wavelength are received on the first to third light receiving surfaces respectively, and a main beam of reflected light of 650 nm in wavelength is received on the first light receiving surface on one side out of the three light receiving surfaces.

Claims

1. An optical pickup device for performing recording or reproduction of information with respect to a plurality of types of optical disks by switchably irradiating three types of laser light having a different wavelength on a recording surface of the optical disk, the optical pickup device comprising:

a first laser emitter for emitting one of the three types of laser light;

a second laser emitter including two types of laser diodes of different wavelength being packaged into a single unit for emitting remaining two types of laser lights out of the three types of laser light;

one or more of diffraction gratings for dividing the laser light emitted from the first and second laser emitters into a plurality of beams;

an optical system for guiding the laser light from the first laser emitter and the second laser emitter to the recording surface of the optical disk and guiding reflected light from the optical disk along the predetermined route;

a beam splitter for splitting the laser light proceeding toward the optical disk and the reflected light from the optical disk; and

an optical sensor for receiving the reflected light split by the beam splitter, wherein;

the optical sensor includes in sequence a first light receiving surface divided into four areas in a matrix manner, a second light receiving surface divided into four areas in a matrix manner, and a third light receiving surface divided into at least two areas aligned in line;

the three-beam reflected light emitted from the first laser emitter and divided enters the first to third light receiving surfaces, and a tracking error signal is generated by differential push-pull method based on the detected result thereof;

the three-beam of one of the wavelength of the reflected light emitted from the second emitter and divided enters the first to third light receiving surfaces, and a tracking error signal is generated by three beam method based on the detected result thereof; and

a main beam of the reflected light of the other wavelength emitted from the second laser emitter enters the first light receiving surface, and a tracking error signal is generated by phase difference detecting method based on the detected result thereof.

2. An optical pickup device for performing recording or reproduction of information with respect to a plurality of types of optical disks by switchably irradiating three types of laser light having a different wavelength on a recording surface of the optical disk, the optical pickup device comprising:

a first laser emitter a first laser emitter for emitting one of the three types of laser light and a second laser emitter for emitting remaining two types of laser light;

one or more of diffraction gratings for dividing the laser light emitted from the first and second laser emitters into a plurality of beams;

an optical system for guiding the laser light from the first laser emitter and the second laser emitter to the recording surface of the optical disk and guiding reflected light from the optical disk along the predetermined route;

a beam splitter for splitting the laser light proceeding toward the optical disk and the reflected light from the optical disk, and

an optical sensor for receiving the reflected light split by the beam splitter, wherein;

the optical sensor comprises in sequence a first light receiving surface divided into four areas in a matrix manner, a second light receiving surface divided into four areas in a matrix manner, and a third light receiving surface divided into at least two areas aligned in line;

the three-beam reflected light emitted from the first laser emitter and divided and the three-beam reflected light of one of the wavelengths emitted from the second laser emitter and divided enter the first to third light receiving surfaces respectively, and a main beam of the reflected light of the other wavelength emitted from the second laser emitter enters the first receiving surface.

3. An optical pickup device according to claim 2, wherein

the second laser emitter is a semiconductor laser comprising two types of laser diodes emitting different wavelengths packaged in one unit.

4. An optical pickup device according to claim 2, wherein:

the tracking error signal is generated by the differential push-pull method based on the result of detection of the reflected light of laser light emitted from the first laser emitter and received onto the first to third light receiving surfaces;

the tracking error signal is generated by the three beam method based on the result of detection of the reflected light of the one wavelength emitted from the second laser emitter and received onto the first to third light receiving surfaces; and

the tracking error signal is generated by the phase difference detecting method based on the result of detection of the reflected light of the other wavelength emitted from the second laser emitter and received onto the first light receiving surface.

5. An optical pickup device according to a claim 2, comprising:

two objective lenses for focusing the laser light to the recording surface of the optical disk, a position switching mechanism for disposing the two objective lenses switchably to the positions where the laser light is guided,

a quarter wave plate connected to the position switching mechanism, the quarter wave plate being disposed on the route of the laser light when one of the objective lenses is disposed to the position where the laser light is guided, and being displaced from the route of the laser light when the other objective lens is disposed at the position where the laser light is guided.