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US 2012/0236261 A1Published application
Fundus camera
AssigneeCanon Kabushiki Kaisha
InventorsKyoji Sekiguchi, Motoya Takai, Toshifumi Masaki
Life of this patent
Estimating the term…
Abstract
A fundus camera that obtains focus evaluation values by scanning, in which a focusing lens moves a predetermined distance according to a photographing mode before the focusing lens starts scanning for obtaining focus evaluation values.
Claims20
A ophthalmologic apparatus comprising:
- an observation photographing optical system having a focusing lens for focusing an image of a fundus of a subject's eye onto an image capturing unit, wherein the image capturing unit has a sensitivity in a visible region and an infrared region;
- an infrared cut filter that is inserted into and retracted from an optical path of the observation photographing optical system;
- a control unit configured to move the focusing lens along the optical path of the observation photographing system, with the infrared cut filter being inserted in the optical path;
- and
- an acquiring unit configured to acquire a signal within a focus detection range of the fundus at each position of the focusing lens in the optical path while the control unit moves the focusing lens along the optical path.
2 more elements
An ophthalmologic method comprising:
- moving a focusing lens for focusing an image of a fundus of a subject's eye onto an image capturing unit along an optical path, with an infrared cut filter being inserted in the optical path;
- and
- acquiring a signal within a focus detection range of the fundus at each position of the focusing lens in the optical path while moving the focusing lens.
An ophthalmologic apparatus comprising:
- a focusing unit disposed in an optical path of a photographing optical system for photographing a fundus of a subject's eye;
- a control unit configured to move the focusing unit in a first direction;
- an acquiring unit configured to acquire a focus evaluation value at each position of the focusing lens in the first direction based on the image of the fundus of the subject's eye;
- and
- a determination unit configured to determine whether a direction in which the focusing unit is moved should be changed from the first direction to a second direction different from the first direction based on a change of the focus evaluation value.
2 more elements
Dependencies are inferred from the claim text.