Patent US4711999A successfully refreshed from Google Patents.
US4711999A
Expired / Lapsed
US
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Apparatus for photometrically detecting an optically focused condition of an optical system
Assignee: Olympus Corp
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Filing: 1987-01-14
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Granted: 1987-12-08
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Expires: 2007-01-14
Abstract
Abstract An apparatus for detecting a focused condition of an optical system, in which a light-receiving means arranged at a fixed position corresponding to a focus position photometrically detects a focused condition. A light beam having a definite shape is projected onto an object to be imaged by a light projection means. The reflected light beam is conducted along an optical axis of the optical system, deflected, and detected by the light receiving means for determining whether a focused condition exists. Several embodiments are disclosed for projecting a light spot of high contrast of the object and for detecting a focused condition on the basis of the intensity distribution of light received by the light-receiving means. The apparatus may be applied to an endoscope and other optical systems.
Inventors
- 👤 Yoshio Shishido
- 👤 Susumu Takahashi
- 👤 Kazumasa Matsuo
- 👤 Atsushi Miyazaki
- 👤 Shinichi Nishigaki
- 👤 Shinichi Kato
- 👤 Takeaki Nakamura
- 👤 Akibumi Ishikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:59
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/30; G02B7/32; G02B23/00; G02B23/24; G02B23/2407
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
258 words
An apparatus for photometrically detecting a focused condition of an image-forming optical system having a first optical axis, comprising: light projection means for projecting a definitely-shaped beam of light onto an object to be imaged; means for conducting light reflected from said object along said first optical axis of said image-forming optical system; beam-splitting means arranged along said first optical axis of said image-forming optical system for partially deflecting said light being reflected from said object along said first optical axis along a second ptical axis and for providing a first light path along said second optical axis; aperture means provided at a location eccentrically of said second optical axis for providing a second light path intersecting said first light path at a point along said second optical axis; and light-receiving means having first and second sides arranged along said second optical axis at a fixed location therealong corresponding to a focal position along said first optical axis of said image-forming optical system and including at least two photoelectric sensor means on said first side having respective photoelectric surfaces thereof arranged perpendicularly to said second optical axis and having a gap between said two photoelectric sensor means for projecting light from said light projecting means through said gap of said light-receiving means, said light projecting means being positioned on said second side of said light-receiving means, wherein a focused condition of said image-forming optical system may be detected photometrically by said light-receiving means in accordance with comparison of respective outputs of said at least two photoelectric sensor means.
Claim 2
Independent Claim
258 words
An apparatus for photometrically detecting a focused condition of an image-forming optical system having a first optical axis, comprising: light projection means for projecting a definitely-shaped beam of light onto an object to be imaged; means for conducting light reflected from said object along said first optical axis of said image-forming optical system; beam-splitting means arranged along said first optical axis of said image-forming optical system for partially deflecting said light being reflected from said object along said first optical axis along a second ptical axis and for providing a first light path along said second optical axis; aperture means provided at a location eccentrically of said second optical axis for providing a second light path intersecting said first light path at a point along said second optical axis; and light-receiving means having first and second sides arranged along said second optical axis at a fixed location therealong corresponding to a focal position along said first optical axis of said image-forming optical system and including at least two photoelectric sensor means on said first side having respective photoelectric surfaces thereof arranged perpendicularly to said second optical axis and having a gap between said two photoelectric sensor means for projecting light from said light projecting means through said gap of said light-receiving means, said light projecting means being positioned on said second side of said light-receiving means, wherein a focused condition of said image-forming optical system may be detected photometrically by said light-receiving means in accordance with comparison of respective outputs of said at least two photoelectric sensor means.
Claim 3
Dependent Claim
54 words
An apparatus as set forth in claim 1, wherein said light projection means include a light source provided on said second optical axis on said second side of said light receiving means, and wherein light from said light source is passed through said aperture means before being projected onto said object to be imaged.
Claim 4
Dependent Claim
54 words
An apparatus as set forth in claim 1 wherein said aperture means comprises an iris having peripheral opening therethrough and a lens between said iris and said first side of said light-receiving means along said second optical axis, at least a peripheral portion of said lens being arranged in optical alignment with said opening.
Claim 5
Dependent Claim
14 words
An apparatus as set forth in claim 3 wherein said opening is a pinhole.
Claim 6
Dependent Claim
14 words
An apparatus as set forth in claim 3 wherein said opening is a slit.
Claim 7
Dependent Claim
16 words
An apparatus as set forth in claim 3 wherein said lens comprises a cylindrical lens portion.
References Cited (Backward Citations)
US3327712A
Cited
JPS4919810A
Cited
US3969575A
Cited
DE2655227A1
Cited
US4153333A
Cited
US4153834A
Cited
US4340811A
Cited
JPS56125713A
Cited
JPS56128923A
Cited
US4521680A
Cited
US4538062A
Cited
US4556787A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-12-07 | 1991-06-08 | 1991-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-07 | 1995-06-08 | 1995-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-07 | 1999-06-08 | 1999-12-08 | $7700.00 | Window Closed / Lapsed |