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. 12, 2004
Filed:
May. 21, 2001
Kouki Kojima, Fukuoka, JP;
Shogo Horinouchi, Fukuoka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An optical pick-up composed of an objective lens and a liquid crystal element, for recording and reproduction of optical discs having different recording densities, the liquid crystal element having nine zones, including: zones 2, 4 located in center parts of half circles of a small diameter beam for a low density optical disc, zones 3, 5 laid along the outer peripheries of zones 2, 4 within the half circles so as to surround zones 2, 4, zones 6, 7 along the outer peripheries of zones 3, 5, between the outer periphery of the small diameter beam and a large diameter beam, extending along substantially half circumferential parts of the small diameter beam, zones 8, 9 extending along substantially half circumferential parts of the large diameter beam, a remainder first zone and including a diameter whose the direction is the same as a tilt direction to be corrected.