OPTICAL PICKUP DEVICE AND OPTICAL DISC DEVICE

• US 20130279319A1
• Filed: 12/05/2011
• Published: 10/24/2013
• Est. Priority Date: 01/21/2011
• Status: Abandoned Application

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Matozaki, Toshiya, Nakahara, Hironori, Takeshita, Nobuo
• Application Number:
  US13/978,486
• Publication Number:
  US 20130279319A1
• Time in Patent Office: Days
• US Class Current: 369/112.24
• CPC Class Codes: G11B 2007/0006 adapted for scanning different types of carrier, e.g. CD & DVD
• CPC Class Codes: G11B 7/08 Disposition or mounting of heads or light sources relatively to record carriers
• CPC Class Codes: G11B 7/0935 Details of the moving parts
• CPC Class Codes: G11B 7/123 Integrated head arrangements, e.g. with source and detectors mounted on the same substrate
• CPC Class Codes: G11B 7/1275 Two or more lasers having different wavelengths
• CPC Class Codes: G11B 7/135 Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
• CPC Class Codes: G11B 7/1356 Double or multiple prisms, i.e. having two or more prisms in cooperation
• CPC Class Codes: G11B 7/1374 Objective lenses optical objectives per se G02B9/00
• CPC Class Codes: G11B 7/1378 Separate aberration correction lenses; Cylindrical lenses to generate astigmatism; Beam expanders
• CPC Class Codes: G11B 7/13925 active, e.g. controlled by electrical or mechanical means

Abstract

An optical pickup device moves in a feed direction parallel to a radial direction of an optical disc rotating on an axis of rotation, and records or reproduces information on an information recording surface of the optical disc. The optical pickup device has a first light source that emits light of a first wavelength, a second light source that emits light of a second wavelength differing from the first wavelength, a first objective lens for focusing the light from the first light source onto the information recording surface, and a second objective lens for focusing the light from the second light source onto the information recording surface. The first and second objective lenses and the first light source are disposed in a plane that passes through the axis of rotation and is parallel to the feed direction.

Claims

1. An optical pickup device that moves in a feed direction parallel to a radial direction of an optical disc rotating around an axis of rotation, and records or reproduces information on an information recording surface of the optical disc, the optical pickup device comprising:

a first light source for emitting light of a first wavelength, the first light source being an optical component;

a second light source for emitting light of a second wavelength differing from the first wavelength, the second light source being an optical component separate from the first light source;

a first objective lens for focusing the light from the first light source onto the information recording surface;

a second objective lens for focusing the light from the second light source onto the information recording surface; and

an optical system for guiding the light from the first and second light sources to the first and second objective lenses, respectively;

wherein

the first and second objective lenses and the first light source are disposed in a plane that passes through the axis of rotation and is parallel to the feed direction;

the second light source is disposed adjacent the first light source in a direction perpendicular to the plane that passes through the axis of rotation and is parallel to the feed direction, and is disposed in such a way that the light emitted from the second light source and the light emitted from the first light source are emitted in mutually identical directions;

at least one of the first light source and the second light source emits an elliptical beam of light and is disposed in such a way that a direction with a wide radiation angle of the elliptical beam of light is oriented parallel to the information recording surface.

9. The optical pickup device of claim 1, wherein at least one of the first light source and the second light source is a semiconductor laser in a flat package having, when seen from the feed direction, a substantially rectangular external shape, and is disposed in such a way that a narrow width direction of the external shape is oriented parallel to the information recording surface.

10. The optical pickup device of claim 9, wherein the semiconductor laser in the flat package is a dual wavelength semiconductor laser for emitting laser light with a wavelength of 680 nm and laser light with a wavelength of 780 nm.

11. The optical pickup device of claim 1, wherein at least one of the first light source and the second light source is a hologram laser unit including a laser element for emitting the light, a photodetector for receiving light returning from the information recording surface, and a hologram element for guiding the light returning from the information recording surface to the photodetector, the hologram laser unit having, when seen from the feed direction, a substantially rectangular external shape, the hologram laser unit being disposed in such a way that a narrow width direction of the external shape is oriented parallel to the information recording surface.

12. An optical disc device comprising:

an optical disc rotating unit onto which the optical disc is loaded and which rotates the optical disc around the axis of rotation; and

the optical pickup device of claim 1, for recording or reproducing information on the optical disc rotating around the axis of rotation.

13. An optical disc device comprising:

an optical disc rotating unit onto which the optical disc is loaded and which rotates the optical disc around the axis of rotation; and

the optical pickup device of claim 9, for recording or reproducing information on the optical disc rotating around the axis of rotation.

14. An optical disc device comprising:

an optical disc rotating unit onto which the optical disc is loaded and which rotates the optical disc around the axis of rotation; and

the optical pickup device of claim 10, for recording or reproducing information on the optical disc rotating around the axis of rotation.

15. An optical disc device comprising:

an optical disc rotating unit onto which the optical disc is loaded and which rotates the optical disc around the axis of rotation; and

the optical pickup device of claim 11, for recording or reproducing information on the optical disc rotating around the axis of rotation.

2-8. -8. (canceled)