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:
Aug. 02, 2005
Filed:
Mar. 19, 2002
Maho Kuwahara, Tokyo, JP;
Katsuo Iwata, Tokyo, JP;
Shintaro Takehara, Yokohama, JP;
Sumitaka Maruyama, Yokohama, JP;
Maho Kuwahara, Tokyo, JP;
Katsuo Iwata, Tokyo, JP;
Shintaro Takehara, Yokohama, JP;
Sumitaka Maruyama, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
The present invention relates to an optical head unit and an optical disk unit using the optical head unit. The head unit includes a wavefront transforming optical element control unit to controls a wavefront transforming optical element so as not to transform wavefront of a light beam focused on a recording layer by a focusing unit due to the thickness error of a light transmission layer positioned between the recording layer and the focusing unit based on an electrical signal outputted from a first light detector, and an output control unit that controls light amount of a light beam radiated by a light emitting unit based on the magnitude of the electrical signal outputted from the light detector.