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:
Oct. 29, 2002
Filed:
Dec. 04, 1997
Masaki Higashihara, Yokohama, JP;
Masato Ikeda, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A focus detecting device for detecting images from different pupil areas on time-shared basis, and detecting the phase difference of the images from the different areas, thereby detecting the defocus amount, is described. The focus detecting device of this type is incapable of exact defocus amount detection, because of the influence of the relative movement between the object and the photographing optical system. The exact defocus amount can be determined by detecting images from a same pupil area on time-shared basis, determining the phase difference between such images and effecting correction corresponding to the phase difference between the images from the same pupil area.