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:
Nov. 28, 2000
Filed:
Apr. 29, 1998
Chih-Hsien Kao, Panchiao, TW;
Sheng-Yunn Wang, Tai-ping, TW;
MediaTek, Inc., , TW;
Abstract
A control device to locate the pickup head on the desired position yielded by the operation of seek is taken in two parts. The first part is utilizing the velocity control to prevent the fluctuation problem of the bi-mass system and the second part is switching the operation to the mode of position control gradually, so that the pickup head can reach the destination precisely and minimize the problem of fluctuation and increase the successful rate of the tracking control. Moreover, this invention has utilized a feedforward control to properly compensate the steady state error originated from the characteristics of system or friction, a position feedback control and a switching factor to gradually switch between the modes of velocity and position. Thus, the position and velocity of the sled motor can be controlled at the same time to allow the pickup head to reach the destination smoothly as expected by the designed of the velocity profile. The tracking control therefore is done smoothly.