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:
Jul. 11, 1995
Filed:
Apr. 22, 1993
Applicant:
Inventor:
Kouji Kaneko, Omiya, JP;
Assignee:
Fuji Photo Optical Co., Ltd., Saitama, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
2502017 ; 354402 ; 348354 ;
Abstract
A novel method and apparatus for auto-focussing which includes determining a focus voltage E.sub.S0 in a current position of a focus lens and focus voltages E.sub.S+ +and E.sub.S- when the focus lens is moved by a distance dx in both a front and rear direction along an optical axis, so that a focussing shift value is calculated more accurately and quick focussing is achieved. A distance X.sub.0 from the current position of the focus lens to the focussing position is calculated based on the focus voltages E.sub.S0, E.sub.S+ and E.sub.S- according to: