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:
Jan. 30, 2007
Yuuichi Kuze, Osaka, JP;
Katsuya Watanabe, Nara, JP;
Yuuichi Kuze, Osaka, JP;
Katsuya Watanabe, Nara, JP;
Panasonic Corporation, Osaka, JP;
Abstract
This optical disc drive can read and/or write data from/on an optical discwith multiple information layers including first and second information layers. The drive includes: a light sourcethat emits the light beam; an objective lens; an actuatorfor moving the objective lens perpendicularly to the information layers; a focus error generatorfor generating a focus error signal representing how much the light beam has been converged on a target one of the information layers; and focus control means for forming a focal point of the light beam on the target information layer by driving the actuator in accordance with the focus error signal. According to the present invention, while a focus jump is being made to shift the focal point of the light beam from the first information layer of the optical discto the second information layer thereof by moving the objective lens, wavelengths and/or numerical apertures for the light beam are changeable while the objective lensis moving.