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:
Apr. 14, 2015
Filed:
Apr. 22, 2009
Tomoyuki Iwanaga, Yokohama, JP;
Nobuyoshi Kishida, Musasahino, JP;
Hideyuki Ohban, Kawaguchi, JP;
Shinya Tanaka, Tokyo, JP;
Tomoyuki Iwanaga, Yokohama, JP;
Nobuyoshi Kishida, Musasahino, JP;
Hideyuki Ohban, Kawaguchi, JP;
Shinya Tanaka, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A fundus camera includes a focus target projection unit including a focus target located at a position conjugate with a fundus of a subject's eye, a split optical element configured to split a light flux passing through the focus target, and a focus target illumination light source configured to illuminate the focus target, a fundus photographing optical system including a focusing lens, a focus link mechanism configured to interlockingly move the focus target projection unit and the focusing lens in a direction of an optical axis, at least two lenses located behind a plane optically conjugate with the imaging plane of the fundus photographing optical system and outside an optical axis of the fundus photographing optical system, image sensors respectively located behind the two lenses, and a phase difference detection unit configured to detect a phase difference between the focus target images based on signals output from the image sensors.