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. 02, 1999
Filed:
Sep. 30, 1998
Hiroshi Takeuchi, Kawasaki, JP;
Kazutoshi Usui, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A motion compensation device having a motion compensation lens which moves to compensate for motion caused by, e.g, hand shake, to prevent blur of an image formed on an image forming plane. An actuator drives the motion compensation lens and when the motion compensation lens moves, a drive current flows in a coil of the actuator. A drive current measuring device measures the drive current. An ideal drive current calculating unit calculates an ideal drive current when the motion compensation lens receives no acceleration. The ideal drive current calculating unit includes a virtual actuator. The virtual actuator is a model of an actuator which behaves similarly to the actual actuator. The ideal drive current calculating unit calculates the ideal drive current for the state in which there is no acceleration caused by hand shake. A position instruction value calculating unit finds a value proportional to the hand shake acceleration by comparing the drive current measured by the drive current measuring device with the ideal drive current calculated by the ideal drive current calculating unit. The position instruction value calculating unit calculates a drive amount (target position signal) of the motion compensation lens which is necessary in order to compensate the motion.