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US4483602A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for detecting a focusing condition of an objective lens

Assignee: Olympus Corp
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Filing: 1982-03-29
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Granted: 1984-11-20
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Expires: 2002-03-29
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Abstract

Abstract In a single-lens reflex camera having an objective lens, a focusing screen and a view finder, a photodetector array is arranged to receive a central part of an object image formed by the objective lens and a focusing condition of the objective lens is detected by calculating an evaluation function from image signals supplied from the photodetectors. A presetting dial for selecting given photodetectors whose image signals are used for detecting the focusing condition is provided at such a position that a part of the dial is exposed to the outside through an opening formed in a rear wall of a camera body at a position underneath a film winding lever. A light emitting diode array is provided on the focusing screen so as to be seen by a user through the view finder. Only desired light emitting diodes are lighted on under the control of a signal supplied by the dial to indicate the region of the photodetector array which is used for detecting the focusing condition.

Inventors

  • 👤 Masahiro Aoki
  • 👤 Kenichi Oinoue
  • 👤 Masatoshi Ida
  • 👤 Asao Hayashi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 23:30
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 175 words
In an apparatus for detecting a focusing condition of an objective lens of an optical device comprising a focusing screen arranged at a position optically conjugated with a predetermined focal plane, a viewfinder for inspecting an image of an object formed on said focusing screen, a photodetector array having a number of photodetectors arranged closely side by side on or near a plane which is optically conjugated with the predetermined focal plane, means for projecting a part of the object image upon said photodetector array, and means for receiving image signals supplied from said photodetectors and for processing the image signals in accordance with a given evaluation function to detect the focusing condition of the objective lens, the improvement comprising: means for selecting an active region portion of said photodetector array for use in detecting the focusing condition, to enable the active region portion to be selectively changed in size and position within the photodetector array to change the size and position of that part of the object image which is used to control focusing.
Claim 2
Dependent Claim 175 words
In an apparatus for detecting a focusing condition of an objective lens of an optical device comprising a focusing screen arranged at a position optically conjugated with a predetermined focal plane, a viewfinder for inspecting an image of an object formed on said focusing screen, a photodetector array having a number of photodetectors arranged closely side by side on or near a plane which is optically conjugated with the predetermined focal plane, means for projecting a part of the object image upon said photodetector array, and means for receiving image signals supplied from said photodetectors and for processing the image signals in accordance with a given evaluation function to detect the focusing condition of the objective lens, the improvement comprising: means for selecting an active region portion of said photodetector array for use in detecting the focusing condition, to enable the active region portion to be selectively changed in size and position within the photodetector array to change the size and position of that part of the object image which is used to control focusing.
Claim 3
Dependent Claim 23 words
An apparatus according to claim 1, further comprising means for displaying in said viewfinder, the selected active region portion of said photodetector array.
Claim 4
Dependent Claim 23 words
An apparatus according to claim 2, wherein said selecting means comprises means for manually selecting the active region portion of said photodetector array.
Claim 5
Dependent Claim 30 words
An appaparatus according to claim 1, wherein said selecting means comprises means for presetting desired photodetectors in the photodetector array whose image signals are used for detecting the focusing condition.
Claim 6
Dependent Claim 57 words
An apparatus according to claim 3, wherein said selecting means comprises a dial rotatably arranged, a movable electrode arranged rotatably together with the dial, a plurality of electrodes arranged fixedly along a moving locus of said movable electrode and a plurality of conductors each for connecting respective one of said fixedly arranged electrodes to said processing means.
Claim 7
Dependent Claim 37 words
An apparatus according to claim 5, wherein said dial is so arranged in a housing of the optical device that a part of the dial is exposed to the outside through an opening formed in said housing.
Claim 8
Dependent Claim 41 words
An apparatus according to claim 6, for use in a camera, wherein said opening through which a part of the dial is exposed to the outside is provided in a rear wall of the camera housing beneath a film winding lever.
Claim 9
Dependent Claim 43 words
An apparatus according to claim 2, wherein said displaying means comprises an array of a plurality of indicating elements arranged closely side by side and means for actuating given indicating elements in the array corresponding to the selected region of the photodetector array.
Claim 10
Dependent Claim 16 words
An apparatus according to claim 8, wherein said indicating elements are arranged on said focusing screen.
Claim 11
Dependent Claim 28 words
An apapratus according to claim 9, wherein said indicating element array is formed by an array of a plurality of light emitting diodes arranged closely side by side.
Claim 12
Dependent Claim 55 words
An apparatus according to claim 10, wherein said actuating means comprises a latch circuit having a plurality of output terminals each connected to respective light emitting diodes and said latch circuit is controlled to store an information signal representing the size of the active region portion of the photodetector array selected by said selecting means.
Claim 13
Dependent Claim 25 words
An apparatus according to claim 11, wherein said latch circuit is so constructed that said information signal denotes light emitting diodes which are not actuated.
Claim 14
Dependent Claim 36 words
An apparatus according to claim 1, wherein said latch circuit is so constructed that said light emitting diodes which are not actuated are selected symmetrically with respect to a center of the light emitting diode array.
Claim 15
Dependent Claim 38 words
An apparatus according to claim 1 wherein said means for selecting an active region includes means for selecting the size of said active region in response to the size of the object image projected upon the photodetector array.
Claim 16
Dependent Claim 39 words
An apparatus according to claim 1 wherein said means for selecting include means for selecting the position of the active region of said photodetector array in response to the size of the object image projected upon the photodetector array.
Claim 17
Independent Claim 86 words
An apparatus for detecting the focusing condition of an objective lens comprising: an objective lens for projecting an object image; means having a detection region including an active region for detecting the focusing condition of the objective lens with respect to a part of an object image; and means for selectively altering the size and position of said active region within the detection region of said means for detecting to change the size and position of that part of the object image used to control focusing.
Claim 18
Independent Claim 86 words
An apparatus for detecting the focusing condition of an objective lens comprising: an objective lens for projecting an object image; means having a detection region including an active region for detecting the focusing condition of the objective lens with respect to a part of an object image; and means for selectively altering the size and position of said active region within the detection region of said means for detecting to change the size and position of that part of the object image used to control focusing.
Claim 19
Dependent Claim 32 words
The apparatus of claim 16 wherein said means for altering said active region includes means for altering the size of said active region in accordance with the size of said object image.
Claim 20
Dependent Claim 30 words
The apparatus of claim 16 wherein said means for altering includes a means for altering the position of the active region in response to the size of the object image.
Claim 21
Dependent Claim 31 words
The apparatus of claim 16 wherein said means for altering includes means for altering the size and position of the active region in response to the size of the object image.

References Cited (Backward Citations)

US3354803A Cited
US4047187A Cited
US4075640A Cited
US4305657A Cited
US4219267A Cited
US4279484A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-11-20 1988-05-21 1988-11-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-11-20 1992-05-21 1992-11-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-11-20 1996-05-21 1996-11-20 $7700.00 Window Closed / Lapsed

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