US 2006/0140078 A1 · Optical pickup device

Abstract

Provided is an optical pickup device capable of suppressing an increase in the number of parts and complication of an optical system while a diffraction grating is used as an optical axis correcting element. Three kinds of blue, red, and infrared laser light beams are emitted from laser element provided in the same CAN package. A blue light emitting point (wavelength: 405 nm) and an infrared light emitting point (wavelength: 780 nm) are arranged in a layer forming direction of the laser elements such that an interval (d2) between the light emitting points becomes shorter than an interval (d1) between each of the light emitting points and a red light emitting point. An optical axis of the laser light beam emitted from the red light emitting point (wavelength: 650 nm) is aligned with an optical axis of the laser light beam emitted from the blue or infrared light emitting point by using the diffraction grating. The number of diffraction gratings for optical axis correction can be made to one and a single photo detector can be commonly used for laser light beams having different wavelengths.

Claims18

Dependent claims

An optical pickup device, comprising:

three laser elements provided in a CAN package, for emitting three kinds of laser light beams of blue, red, and infrared light beams to a recording medium, a blue light emitting point and an infrared light emitting point being arranged in a layer forming direction of the laser elements so that an interval (d2) between the blue light emitting point and the infrared light emitting point becomes smaller than an interval (d1) between one of the blue light emitting point and the infrared light emitting point and a red light emitting point;
and
a diffraction grating for aligning an optical axis of a laser light beam emitted from the red light emitting point with an optical axis of a laser light beam emitted from one of the blue light emitting point and the infrared light emitting point.

An optical pickup device, comprising:

a semiconductor laser including three laser elements provided in a CAN package, for generating three kinds of laser light beams including a laser light beam for next-generation DVD, a laser light beam for DVD, and a laser light beam for CD, a first light emitting point of the laser light beam for next-generation DVD and a second light emitting point of the laser light beam for CD being arranged in a layer forming direction of the laser elements so that an interval (d2) between the first light emitting point and the second light emitting point becomes smaller than an interval (d1) between one of the first light emitting point and the second light emitting point and a third light emitting point of the laser light beam for DVD;
and
a diffraction grating for aligning an optical axis of the laser light beam for DVD with one of an optical axis of the laser light beam for next-generation DVD and an optical axis of the laser light beam for CD.

Dependencies are inferred from the claim text.

Optical pickup device

Life of this patent

Optical pickup device

Life of this patent

Abstract

Claims18