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. 25, 2003
Filed:
Apr. 18, 2001
Takanori Okada, Moriguchi, JP;
Shuichi Yoshida, Osaka, JP;
Masaharu Imura, Neyagawa, JP;
Kiyoshi Masaki, Amagasaki, JP;
Kazuhiro Mihara, Moriguchi, JP;
Tsutomu Kai, Katano, JP;
Noritaka Akagi, Osaka, JP;
Masanori Harui, Minoh, JP;
Kazuhiko Kouno, Takatsuki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka-fu, JP;
Abstract
In a method of the present invention for controlling stepping motor, the stepping motor driving current is increased or reduced at a fixed inclination in proportion to the time to control the stepping motor effectively, and, a stepping motor driving current pattern is changed by ¼ cycle or more to synchronize the state of excitation between the stepping motor driving means and the stepping motor to control the pick-up very accurately. In addition, the disk apparatus of the present invention, which uses a stepping motor is provided with a pulse rate pattern variable means, a pulse rate change proportion measuring means, and a driving voltage variable means, and when the pulse rate and the pulse rate change proportion are low, the driving voltage amplitude is lowered to reduce surplus torque generation in the stepping motor.