The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 16, 2003
Filed:
Sep. 28, 2000
Shoichi Kyoya, Miyagi-ken, JP;
Tatsumaro Yamashita, Miyagi-ken, JP;
Alps Electric Co., Ltd., Tokyo, JP;
Abstract
A compound optical unit includes a housing mounted on an optical pickup apparatus, the housing has a semiconductor laser device, a light receiving device, and a compound optical device, fixed to the housing. The semiconductor laser device includes a laser diode for emitting shorter wavelength laser beams for a DVD and another laser diode for emitting longer wavelength laser beams for a CD. The compound optical device includes an incidence surface and an emission surface for receiving and emitting, respectively, the light beams emitted by the semiconductor laser device, a diffraction lattice provided on the emission surface for diffracting light beams reflected and returned from an optical disk, and a reflective surface for reflecting the light beams diffracted by the diffraction lattice toward the light receiving device. The reflective surface is provided with a correction element for focusing the light beams of different wavelengths on one light receiving position of the light receiving device.