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:
Nov. 16, 2010
Filed:
Jan. 25, 2005
Minoru Ohyama, Kanagawa-ken, JP;
Minoru Ohyama, Kanagawa-ken, JP;
Victor Company of Japan, Limited, Yokohama-shi, JP;
Abstract
An optical device diffracts incident light with a hologram element and receives the diffracted light with light receiving facesA toon a light receiving element. Reflected sub-beams used for a tracking operation are received with different ones of the light receiving faces depending on the wavelengths of the reflected sub-beams. When first light receiving faces, andare receiving an incident beam of a first wavelength, output signals from the first light receiving faces and output signals from the other light receiving faces, andare processed to detect an unnecessary light component. The optical device can record and/or reproduce information signals to and/or from optical discs such as DVDs and CDs which need light sources of different wavelengths, without the influence of unnecessary reflected light from the optical discs or without complicating operation of output signals.