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. 10, 2010
Filed:
Feb. 27, 2006
Fumio Isshiki, Yokohama, JP;
Hiromitsu Mori, Fujisawa, JP;
Fumio Isshiki, Yokohama, JP;
Hiromitsu Mori, Fujisawa, JP;
Hitachi Media Electronics Co., Ltd., Iwate, JP;
Abstract
In an information reproducing apparatus in which a liquid crystal lens element is used for the selection and switching of layers, the instability of servo control during the switching of the layers due to the overlapping of signals from two layers is eliminated and the focal point is shifted onto the correct switched layer. During the switching of the liquid crystal lens, a focus bias is added depending on the direction in which the layers are switched so as to stabilize servo control. Alternatively, the objective lens is held during the switching and after the switching of the liquid crystal lens element, the hold state is released in synchronization with the rotation of the disk.