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. 27, 2008
Filed:
Jun. 01, 2004
Cheng-li Chang, Taipei, TW;
Cheng-Li Chang, Taipei, TW;
Behavior Tech Computer Corp., Taipei, TW;
Abstract
The invention is disclosed a method for promptly protecting a voice coil motor in an optical disk drive. A step (A) allows a data signal processor (DSP) to execute a protect module of the voice coil motor every preset time interval. In a step (B), the DSP executes following further steps during executing the protect module. A step (b1) reads tracking error (TE)/focusing error (FE) and determines if the TE/FE is over a safety range. A step (b2) starts a gain decrease operation of a signal amplifier if the TE/FE in step (b1) has been over the safety range for more than the first preset number of times so as to lower the control current outputting to the voice coil motor. A step (b3) starts an operation of speed reduction and a low current operation of a controller to secure the voice coil motor being safe if the TE/FE in step (b1) has been over the safety range for more than a second preset number of times.