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. 10, 2011
Filed:
Apr. 28, 2009
Shigeki Yamazaki, Matsudo, JP;
Tomomi Okamoto, Yokohama, JP;
Kazuki Nakazawa, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi-LG Data Storage, Inc., Tokyo, JP;
Abstract
The present invention provides an optical disc apparatus that reduces access time while suppressing the emanation of heat from a beam expander. A microcomputer manages the operation time and pause time of a stepping motor constructed to move the movable lens of the beam expander, and in accordance with the duration of an immediately previous pause, limits the number of successive stepping-motor driving actions following the pause time, below a maximum permissible count. When the pause duration is shorter than a threshold value or when the number of successive stepping-motor driving actions reaches the maximum permissible count, the microcomputer starts next driving of the stepping motor after a required waiting time.