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:
Oct. 21, 1997
Filed:
Oct. 13, 1995
Hideya Seki, Suwa, JP;
Masatoshi Yonekubo, Suwa, JP;
Toshio Arimura, Suwa, JP;
Takashi Takeda, Suwa, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
A laser emission unit for use in an optical head performs a plurality of functions which are integrated. A laser beam from the laser emission unit mounted in a lens holder is emitted through an objective lens and is focused on an optical medium. A reflected beam from the optical medium returns through the objective lens and a diffraction grating to a signal detection circuit in the laser emission unit. Since the laser emission unit performs a plurality of functions, the space for various elements otherwise required in the optical head can be eliminated. The space for an additional light path for the reflected beam is also eliminated. Therefore, the size of the optical head is very small. Since the optical head can be assembled by using a small number of parts, the production costs can be reduced. Furthermore, the optical head can shield the noises by using the housing and/or the lens holder itself.