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:
Aug. 16, 2011
Filed:
Apr. 28, 2010
Katsumi Karasawa, Utsunomiya, JP;
Katsumi Karasawa, Utsunomiya, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
An automatic focusing apparatus includes: a focus detector photoelectrically converting at least a part of a photographing beam; a defocus computer calculating a defocus amount based on an output of the focus detector; a driver driving a focus lens based on the defocus amount; and a unit setting a maximum time period for charge accumulation in the focus detector. If the accumulated charge in the focus detector reaches a threshold within the period, when the accumulated charge in the focus detector reaches the threshold, the defocus computer calculates a defocus amount using an output of the focus detector and outputs the defocus amount to the driver. If the accumulated charge in the focus detector does not reach the threshold within the period, when the period lapses, the defocus computer calculates a defocus amount using an output of the focus detector and outputs the defocus amount to the driver.