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:
Sep. 02, 2008
Filed:
Feb. 21, 2006
Shingo Fukamizu, Takatsuki, JP;
Yasunori Yamamoto, Hirakata, JP;
Shuji Tamaoka, Nagaokakyo, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
Optical disc drives designed for reduced power consumption switch the supply voltage in three stages between first, second, and third power supplies. The reduction in power consumption that is possible in the focusing and tracking drive circuits with three stage switching control is limited. This drive apparatus enables further reductions in power consumption. A drive output tracking signal is generated according to the drive conditions of the focusing or tracking drive circuit. The drive output tracking signal is applied to the drive circuit power supply, and the power supply is controlled according to the drive output tracking signal. A power supply change detector detects sudden changes in the drive output tracking signal, and inputs the detection signal to the DSP controlling the entire system. The DSP determines whether to improve the power supply response by comparison with predetermined conditions, and returns the result to the power supply.