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:
Feb. 18, 2020
Filed:
Nov. 16, 2017
Olympus Corporation, Hachioji-shi, Tokyo, JP;
Yuko Watanabe, Hachioji, JP;
Olympus Corporation, Tokyo, JP;
Abstract
A controller within a lens drive device, the controller comprising an open loop control section that performs open loop control of the stepping motor using a given excitation position change and a given drive voltage, and a closed loop control section that, at the time of rotating the stepping motor, calculates tracking lag for change in rotational position for change in excitation position, and performs closed loop control of drive speed and drive voltage of the stepping motor in accordance with a control error, which is a difference between target tracking lag and tracking lag, wherein the closed loop control section performs at least open loop control of drive voltage during an acceleration operation of the stepping motor, as well as closed loop control of drive voltage and drive speed in accordance with control error by transitioning to closed loop control of drive voltage when an acceleration operation is completed.