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:
Jun. 02, 1998
Filed:
Sep. 23, 1996
Jun-ichi Takahashi, Tokyo, JP;
NEC Corporation, , JP;
Abstract
The optical head device includes a laser light source, a beam splitter for reflecting light emitted from the laser light source, a converging lens for converging light reflected from the beam splitter as a minute beam spot on a recording surface of an optical disk medium, a photo-detector for receiving modulated reflected light from the recording surface of the optical disk medium through the converging lens and the beam splitter, and a diffraction grating disposed between the laser light source and the beam splitter. The device is featured by the provision of a variable aperture element which is disposed between the converging lens and the beam splitter and which is capable of controlling the transmission and blocking of the light depending on the polarization directions. The arrangement enables the reproduction of the data recorded in optical disk media having different thicknesses by a single objective lens.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile