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:
May. 03, 2011
Filed:
Oct. 09, 2007
Hirotaka Miyamoto, Kanagawa, JP;
Kimihiro Saito, Saitama, JP;
Hirotaka Miyamoto, Kanagawa, JP;
Kimihiro Saito, Saitama, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical disc apparatus and a focus position control method can highly accurately record recording marks representing information on or reproduce such recording marks from an optical disc. A blue light beam is irradiated onto the target depth to be irradiated by driving an objective lens to focus a red light beam in a reflection/transmission film formed in the optical disc and displacing a movable lens, which is a focus moving section, of a relay lens. A blue light reflection region is formed as part of the reflection/transmission film and the position of the blue light reflection region where the red light focus and the blue light focus are aligned is defined as reference position. The movable lens is displaced by an arbitrarily selected quantity from the reference position according to the target depth.