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:
Jun. 07, 1994
Filed:
Jan. 28, 1993
Minoru Hara, Hachioji, JP;
Kazuhiro Satoh, Sagamihara, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
A lens barrel drive unit for a camera, in which the present invention is implemented, comprises a lens barrel that is a moving object having a female screw, a drive screw that includes a male screw which engages with the female screw and that moves the lens barrel back and forth with the rotation of the male screw, a drive source for rotating the drive screw, a signal generator for generating a pulse signal according to the rotation of the drive source or drive screw, a first memory that stores a difference between a theoretical lead and an actual lead of the drive screw as a correction coefficient, a second memory that stores the theoretical number of pulses associated with a quantity of rotation of the drive screw which is required to drive the lens barrel to a given position corresponding to a subject distance, and a computing unit that uses the correction coefficient and the theoretical number of pulses to compute the actual number of pulses required for extending the lens barrel.