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:
Jan. 31, 2006
Filed:
Jun. 12, 2002
Kenji Yamamoto, Kanagawa, JP;
Kiyoshi Osato, Chiba, JP;
Yoshiaki Kato, Tokyo, JP;
Sony Corporation, , JP;
Abstract
An optical pickup device including a light source, an objective lens for converging a light beam emitted from the light source at a signal recording surface of an optical recording medium and irradiating the signal recording surface of the optical recording medium with the light beam, and a liquid crystal device, disposed in a light path between the light source and the objective lens, for giving a predetermined phase distribution to transmission light that passes through the liquid crystal device, with both front and back surfaces of the liquid crystal device being flat surfaces. In the optical pickup device, the liquid crystal device is constructed by sandwiching a liquid crystal molecule layer by a pair of transparent substrate. In addition, a liquid-crystal-molecule-layer-sandwiching-side surface of each transparent substrate has a shape that is formed when a thickness distribution of the liquid crystal molecule layer is similar to a phase distribution that is produced when a predetermined aberration occurs.