Patent US4845353A successfully refreshed from Google Patents.
US4845353A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focus detecting system
Assignee: Minolta Co Ltd
•
Filing: 1987-06-24
•
Granted: 1989-07-04
•
Expires: 2007-06-24
Abstract
Abstract A focus detecting system of a type comprising a transducer element array arranged in a vertical direction for detecting through a reflecting member a standard light flux and a reference light fluxes which have passed through different areas of a plane of an exit pupil of the photo-taking lens. The reflecting member is supported for pivotal movement between a downwardly pivoted position at which both of the standard and reference light fluxes are reflected downwards, and an upwardly pivoted position at which it is retracted out of the optical axis. The reflecting member when in the downwardly pivoted position causes the standard light flux to be reflected at a first reflecting surface area of the reflecting member adjacent the pivot axis and also causes the reference light flux to be reflected at a second reflecting surface area of the reflecting member remote from the pivot axis.
Inventors
- 👤 Toshihiko Karasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:58
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/34; G02B7/346
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
195 words
A focus detecting system for detecting focusing condition of a photo-taking lens, comprising; means for reflecting light passed through the photo-taking lens in a first position, said reflecting means being rotatable to a second position with respect to a predetermined rotatable axis for retracting from an area through which photo-taking light passes for photographing, and said reflecting means including a first portion located nearby the rotational axis and a second portion located far from the rotational axis, said first portion being smaller than said second portion; means for receiving light reflected by the reflecting means located at the first position, said receiving means including a first receiving portion for receiving light reflected by the first portion of the reflecting means and a second receiving portion for receiving light reflected by the second portion of the reflecting means, said receiving means further including a plurality of light receiving elements arranged in a direction perpendicular to the rotational axis of the reflecting means; and a calculating means for calculating defocus of the photo-taking lens by comparing the light receiving condition of the first receiving portion of the receiving means with that of the second receiving portion thereof.
Claim 2
Dependent Claim
195 words
A focus detecting system for detecting focusing condition of a photo-taking lens, comprising; means for reflecting light passed through the photo-taking lens in a first position, said reflecting means being rotatable to a second position with respect to a predetermined rotatable axis for retracting from an area through which photo-taking light passes for photographing, and said reflecting means including a first portion located nearby the rotational axis and a second portion located far from the rotational axis, said first portion being smaller than said second portion; means for receiving light reflected by the reflecting means located at the first position, said receiving means including a first receiving portion for receiving light reflected by the first portion of the reflecting means and a second receiving portion for receiving light reflected by the second portion of the reflecting means, said receiving means further including a plurality of light receiving elements arranged in a direction perpendicular to the rotational axis of the reflecting means; and a calculating means for calculating defocus of the photo-taking lens by comparing the light receiving condition of the first receiving portion of the receiving means with that of the second receiving portion thereof.
Claim 3
Dependent Claim
33 words
A focus detecting system as claimed in claim 1, wherein the number of the light receiving elements included in the first receiving portion is smaller than that included in the second receiving portion.
Claim 4
Dependent Claim
60 words
A focus detecting system as claimed in claim 1, wherein the first portion of the reflecting means reflects light having passed a first area defined in an exit pupil of the photo-taking lens while the second portion of the reflecting means reflects light having passed through a second area which is different from the first area in the exit pupil.
Claim 5
Dependent Claim
51 words
A focus detecting system as claimed in claim 1, further comprising a main mirror for reflecting light passed through the photo-taking lens to guide the light towards a finder optical system, and means for pivotally supporting the reflecting means by the main mirror at the rearward side of the main mirror.
Claim 6
Dependent Claim
264 words
A focus detecting system for detecting focusing condition of a photo-taking lens, comprising: means for reflecting light passed through the photo-taking lens with an optical axis of the photo-taking lens in a first position, said reflecting means being rotatable to a second position with respect to a predetermined rotatable axis for retracting from an area through which photo-taking light passes for photographing, and said reflecting means including a first portion located nearby the rotational axis and a second portion location far from the rotational axis; first means, located at a position through which the reflected optical axis of the photo-taking lens passes, for receiving light reflected by the reflecting means, said first receiving means including a plurality of light receiving elements arranged perpendicularly to the optical axis; second means, for receiving light reflected the reflecting means, including, a first receiving portion, containing a plurality light receiving elements arranged perpendicularly to the plurality of light receiving elements of the first receiving means, for receiving light reflected by the first portion of the reflecting means, and a second receiving portion, containing a plurality of light receiving elements arranged perpendicularly to the plurality of light receiving elements of the first receiving means, for receiving light reflected by the second portion of the reflecting means, said plurality of light receiving elements contained in the first and second receiving portions being arranged perpendicularly to the rotational axis of the reflecting means; and means for calculating defocus of the photo-taking lens on the basis of outputs of the plurality of light receiving elements in the first and second receiving means.
Claim 7
Dependent Claim
264 words
A focus detecting system for detecting focusing condition of a photo-taking lens, comprising: means for reflecting light passed through the photo-taking lens with an optical axis of the photo-taking lens in a first position, said reflecting means being rotatable to a second position with respect to a predetermined rotatable axis for retracting from an area through which photo-taking light passes for photographing, and said reflecting means including a first portion located nearby the rotational axis and a second portion location far from the rotational axis; first means, located at a position through which the reflected optical axis of the photo-taking lens passes, for receiving light reflected by the reflecting means, said first receiving means including a plurality of light receiving elements arranged perpendicularly to the optical axis; second means, for receiving light reflected the reflecting means, including, a first receiving portion, containing a plurality light receiving elements arranged perpendicularly to the plurality of light receiving elements of the first receiving means, for receiving light reflected by the first portion of the reflecting means, and a second receiving portion, containing a plurality of light receiving elements arranged perpendicularly to the plurality of light receiving elements of the first receiving means, for receiving light reflected by the second portion of the reflecting means, said plurality of light receiving elements contained in the first and second receiving portions being arranged perpendicularly to the rotational axis of the reflecting means; and means for calculating defocus of the photo-taking lens on the basis of outputs of the plurality of light receiving elements in the first and second receiving means.
Claim 8
Dependent Claim
28 words
A focus detecting system as claimed in claim 5, wherein said second receiving means is located at a position through which the reflected optical axis does not pass.
Claim 9
Dependent Claim
112 words
A focus detecting system as claimed in claim 6, further comprising; third means, located at a position symmetrical with the second means with respect to the optical axis, for receiving light reflected by the reflecting means, including, a first receiving portion, containing a plurality of light receiving elements arranged perpendicularly to the plurality of light receiving elements of the first receiving means, for receiving light reflected by the first portion of the reflecting means, and a second receiving portion, containing a plurality of light receiving elements arranged perpendicularly to the plurality of light receiving elements of the first receiving means, for receiving light reflected by the second portion of the reflecting means.
References Cited (Backward Citations)
US3529528A
Cited
US3708619A
Cited
US3860935A
Cited
US4293205A
Cited
US4431285A
Cited
JPS5849844A
Cited
US4580042A
Cited
US4636624A
Cited
US4660955A
Cited
US4721975A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |