Patent US3732001A successfully refreshed from Google Patents.
US3732001A
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Automatic lens focusing method and apparatus
Assignee: Individual
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Filing: 1971-02-22
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Granted: 1973-05-08
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Expires: 1991-02-22
Abstract
Abstract An automatic lens focusing method and apparatus is disclosed wherein advantage is taken of the geometrical optics of out-offocus images by varying the effective aperture of an image forming lens to produce relative motion of the out-of-focus portions of the formed image. A motion detector at the imaging plane generates a signal in response to motion of the out-offocus portions of the formed image which may then be used for control of the image-forming lens to provide optimum focusing or to provide range finding information.
Inventors
- 👤 W Harrison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:45
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36; G03; G03B; G03B21/00; G03B21/14; G03B21/53
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
349 words
Apparatus for determining degree of focus comprising: a beam splitter for receiving incident light from an object whose image is to be formed and providing first and second beams; first image-forming lens interposed in the path of the first beam; first image motion detector spaced from the first lens in a position to receive an image formed by the first lens, said motion detector being designed to generate a signal in response to the quantum of image motion of the image formed on said motion detector; masking means mounted adjacent the first lens in a position to interrupt a portion of the light passing through the first lens onto the first motion detector; means for moving said masking means to produce motion of the out-of-focus portion of the image formed on the first motion detector whereby a signal S1 is generated in response to motion of the out-of-focus portion of the formed image on the first motion detector, motion of the formed image produced by motion of the object whose image is being formed, and motion of the formed image produced by motion of the apparatus relative to the object; second image-forming lens with characteristics matching the first image-forming lens, interposed in the path of the second beam; second motion detector spaced from the second Image-forming lens in a position to receive an image formed by said second lens, said second motion detector also being designed to generate a signal in response to motion of the image formed on the second motion detector, whereby a second signal S2 is generated in response to motion of the object whose image is to be formed and motion of the apparatus relative to the object; a signal inverter to which one of the generated signals is fed to thereby provide a signal substantially equal in value and opposite in sign to the signal fed into the signal inverter; and a signal adder to which the output of the signal inverter and the other signal are fed to thereby provide a signal in response to the degree of focus of the formed images.
Claim 2
Dependent Claim
349 words
Apparatus for determining degree of focus comprising: a beam splitter for receiving incident light from an object whose image is to be formed and providing first and second beams; first image-forming lens interposed in the path of the first beam; first image motion detector spaced from the first lens in a position to receive an image formed by the first lens, said motion detector being designed to generate a signal in response to the quantum of image motion of the image formed on said motion detector; masking means mounted adjacent the first lens in a position to interrupt a portion of the light passing through the first lens onto the first motion detector; means for moving said masking means to produce motion of the out-of-focus portion of the image formed on the first motion detector whereby a signal S1 is generated in response to motion of the out-of-focus portion of the formed image on the first motion detector, motion of the formed image produced by motion of the object whose image is being formed, and motion of the formed image produced by motion of the apparatus relative to the object; second image-forming lens with characteristics matching the first image-forming lens, interposed in the path of the second beam; second motion detector spaced from the second Image-forming lens in a position to receive an image formed by said second lens, said second motion detector also being designed to generate a signal in response to motion of the image formed on the second motion detector, whereby a second signal S2 is generated in response to motion of the object whose image is to be formed and motion of the apparatus relative to the object; a signal inverter to which one of the generated signals is fed to thereby provide a signal substantially equal in value and opposite in sign to the signal fed into the signal inverter; and a signal adder to which the output of the signal inverter and the other signal are fed to thereby provide a signal in response to the degree of focus of the formed images.
Claim 3
Dependent Claim
42 words
Apparatus for determining degree of focus as set forth in claim 1 wherein said masking means and means for moving said masking means vary the position of the effective aperture of the first lens while maintaining a substantially constant effective aperture area.
Claim 4
Dependent Claim
51 words
Apparatus for determining degree of focus as set forth in claim 2 further provided that the masking means and means for moving the masking means comprise an opaque mask of predetermined shape pivotally mounted for rotation about the optical axis of the first lens and means for rotating said opaque mask.
Claim 5
Dependent Claim
36 words
Apparatus for determining degree of focus as set forth in claim 1 wherein said first and second motion detectors each comprise a photodetector having a photosensitive surface over which is formed a grid of opaque portions.
Claim 6
Dependent Claim
24 words
Apparatus for determining degree of focus as set forth in claim 4 wherein said grid comprises a plurality of parallel strips of opaque material.
Claim 7
Dependent Claim
50 words
Apparatus for determining degree of focus as set forth in claim 4 wherein there is further provided at the output of each photodetector, differentiating circuit means to which the output of the photodetector is fed to thereby provide a signal in response to variations in the output of the photodetector.
Claim 8
Dependent Claim
46 words
Apparatus for determining degree of focus as set forth in claim 6 wherein there is further provided at the output of each differentiating circuit, rectifier circuit means and filter means to which the output of the differentiating circuit means is fed to provide a smoothed signal.
Claim 9
Dependent Claim
320 words
Automatic lens focusing apparatus comprising image forming lens means; a beam splitter spaced from said lens means providing first and second beams from light passing through said lens means; first image motion detector interposed in the path of the first beam and spaced from said beam splitter in a position to receive an image formed by said lens means, said motion detector being designed to generate signal in response to motion of the image formed thereon; masking means interposed in the path of said first beam mounted adjacent said beam splitter in position to interrupt a portion of the light comprising the first beam of light passing from said beam splitter onto said first motion detector; means for moving said masking means to cause motion of the out-of-focus portion of the image formed on said motion detector whereby a signal is generated in response to motion of the out-of-focus portion of the formed image, motion of the image produced by the motion of the object whose image is being formed and motion of the image produced by motion of the apparatus relative to the object; second motion detector interposed in the path of the second beam of light and spaced from said beam splitter in a position to receive an image formed by said lens means, said second motion detector being designed to generate signal in response to motion of the image formed thereon whereby a second signal is generated in response to motion of the image produced by motion of the object whose image is being formed, and motion of the image produced by motion of the apparatus relative to the object; a signal inverter to which one of the two generated signals is fed; and a signal adder to which the output of the signal inverter and the other sIgnal are fed to thereby produce a signal in response to the degree of focus of the formed images.
Claim 10
Dependent Claim
320 words
Automatic lens focusing apparatus comprising image forming lens means; a beam splitter spaced from said lens means providing first and second beams from light passing through said lens means; first image motion detector interposed in the path of the first beam and spaced from said beam splitter in a position to receive an image formed by said lens means, said motion detector being designed to generate signal in response to motion of the image formed thereon; masking means interposed in the path of said first beam mounted adjacent said beam splitter in position to interrupt a portion of the light comprising the first beam of light passing from said beam splitter onto said first motion detector; means for moving said masking means to cause motion of the out-of-focus portion of the image formed on said motion detector whereby a signal is generated in response to motion of the out-of-focus portion of the formed image, motion of the image produced by the motion of the object whose image is being formed and motion of the image produced by motion of the apparatus relative to the object; second motion detector interposed in the path of the second beam of light and spaced from said beam splitter in a position to receive an image formed by said lens means, said second motion detector being designed to generate signal in response to motion of the image formed thereon whereby a second signal is generated in response to motion of the image produced by motion of the object whose image is being formed, and motion of the image produced by motion of the apparatus relative to the object; a signal inverter to which one of the two generated signals is fed; and a signal adder to which the output of the signal inverter and the other sIgnal are fed to thereby produce a signal in response to the degree of focus of the formed images.
Claim 11
Dependent Claim
48 words
Automatic lens-focusing apparatus as set forth in claim 8 wherein each of said motion detectors comprises a photodetector having a photosensitive surface with a grid of opaque material formed thereon and wherein there is also provided differentiating circuit means to which the output of said photodetector is fed.
References Cited (Backward Citations)
US2524807A
Cited
DE1087372B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |