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. 29, 1994
Filed:
Nov. 12, 1992
Toshiaki Kitamura, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A focus detecting method includes the step of projecting the real image of an observation object including a plurality of object patterns onto an image pickup device through an optical system and producing image data from an output of the image pickup device, the step of calculating correlation values of the image data of each of the plurality of object patterns and the image data of a prestored reference pattern while varying the relative positional relation among the image pickup device, the optical system and the observation object in the direction of the optical axis of the optical system, and the step of judging a relative positional relation giving the maximum correlation value as an in-focus state. An apparatus is provided for carrying out the above-described focus detecting method.