EP0465671A1
Expired / Lapsed
EP
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Focus detecting device
Assignee: Nikon Corp
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Filing: 1991-01-29
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Granted: —
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Expires: 2011-01-29
Abstract
Abstract A focus detecting device for a camera and the like, capable of detecting a focus at a position vertically spaced apart from the optical axis of a taking lens indepednently of the position of an exit pupil of an interchangeable taking lens. The range of a detected picture image used for the focus detecting is restricted to a region smaller than the range of a detected picture image used in the conventional refocusing type camera, setting of the used region on an image sensor is changed in accordance with the position of the exit pupil of the taking lens and the position of an aperture of a refocusing lens (a position spaced vertically apart from the optical axis), namely, a region changing means is provided for changing the setting of an image shift calculation region where the image shifts are compared with each other, thereby enabling the detection of the focus with no eclipse.
Inventors
- 👤 Ken Utagawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:24
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/34; G02B7/346
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
172 words
A focus detection apparatus which comprises a plurality of aperture portions behind a predetermined imaging plane of a photographing lens, and an image sensor portion arranged behind the plurality of aperture portions, and consisting of a plurality of photoelectric elements for detecting a plurality of light amount distributions by a plurality of light beams passing through the aperture portions, and calculates a relative shift amount of images using photoelectric outputs from said plurality of photoelectric elements to perform focus detection, characterized by comprising: lens information storage means for storing lens information representing optical characteristics of said photographing lens; region setting means for changing a pair of use regions on said image sensor portion, which regions are used upon detection of a relative displacement of images on the basis of the light amount distributions in accordance with the lens information and positions of the aperture portions for guiding light to the corresponding photoelectric elements, and image shift calculation means for calculating a relative shift amount of images for the pair of use regions.
Claim 2
Dependent Claim
53 words
A focus detection apparatus according to claim 1, characterized in that said lens information storage means comprises exit pupil position storage means for storing a position of an exit pupil of said photographing lens, and said region setting means changes the use regions on the basis of the position of the exit pupil.
Claim 3
Dependent Claim
45 words
A focus detection apparatus according to claim 1, characterized in that said lens information storage means comprises full-open F number storage means for storing a full-open F number, and said region setting means changes the use regions on the basis of the full-open F number.
Claim 4
Dependent Claim
39 words
A focus detection apparatus according to claim 1, characterized by further comprising correction means for correcting an image shift calculation result by said image shift calculation means in accordance with the use regions set by said region setting means.
Claim 5
Dependent Claim
35 words
A focus detection apparatus according to claim 1, characterized in that said region setting means changes read ranges of the photoelectric outputs from said plurality of photoelectric elements corresponding to the pair of use regions.
Claim 6
Dependent Claim
256 words
A focus detection apparatus which comprises at least three aperture portions behind a predetermined imaging plane of a photographing lens, and an image sensor portion arranged behind the at least three aperture portions, and consisting of a plurality of photoelectric elements for detecting a plurality of light amount distributions by a plurality of light beams passing through the aperture portions, and calculates an image shift amount on the predetermined imaging plane using photoelectric outputs from said plurality of photoelectric elements to perform focus detection, characterized by comprising: first image shift calculation means for calculating a relative shift amount of images on the basis of a light amount distribution of a first portion of the light amount distribution associated with a light beam passing through the first aperture portion, and a light amount distribution associated with a light beam passing through the second aperture portion; and second image shift calculation means for calculating a relative shift amount of images on the basis of a light amount distribution of a second portion, which is different from the first portion although the second portion is allowed to partially overlap the first portion, in the light amount distribution associated with the light beam passing through the first aperture portion, and a light amount distribution associated with a light beam passing through the third aperture portion different from the first and second aperture portions, and characterized in that focus detection is performed on the basis of a result from at least one of said first and second image shift calculation means.
Claim 7
Dependent Claim
194 words
A focus detection apparatus characterized by comprising: an image sensor portion which has at least three aperture portions for receiving light from an object, and if the aperture portions are represented by A(1), A(2), A(3),..., A(n), comprises an image sensor portion P(i) arranged behind the aperture portions, and consisting of a plurality of photoelectric elements for detecting a first portion of a light amount distribution by light beams passing through the aperture portions A(i), and an image sensor portion Q(i) consisting of a plurality of photoelectric elements for detecting a second portion of the light amount distribution, said image sensor portions being arrayed in the order of P(1), Q(1), P(2), Q(2), P(3), Q(3),..., P(n), and Q(n); and image shift calculation means for, when a predetermined positive integer is represented by s, calculating a relative shift amount of images on the basis of an image output from the image sensor portion P(i) and an image output from the image sensor portion Q(i+s), and characterized in that said image shift calculation means calculates an image shift amount on the basis of a pair of photoelectric outputs associated with at least one i to perform focus detection.
References Cited (Backward Citations)
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