US3682071A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic focusing device for cameras
Assignee: Canon Inc
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Filing: 1970-11-05
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Granted: 1972-08-08
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Expires: 1990-11-05
Abstract
Abstract An automatic focusing device for cameras projects from the camera to an object to be photographed a spot of light whose intensity is modulated. The light reflected by the object is received by a range-finding lens and this received light is divided to form two images on two photoelectric effect elements, respectively, through an optical system which produces the two images with an apparent parallax except when the object is sharply in focus. The range-finding lens is movable with the phototaking lens and is shifted back and forth by the signal output from the photoelectric effect elements which signal varies depending upon whether or not the images on both photoelectric effect elements are free from apparent parallax.
Inventors
- 👤 Kazuya Hosoe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:29
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/48; G01S7/481; G01S7/4811; G02; G02B; G02B7/00; G02B7/28; G02B7/34; G02B7/343
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
118 words
An automatic focusing system for cameras comprising in combination means for projecting from a camera to an object a spot of light whose intensity is modulated, an adjustable focus lens for producing at said camera an image of said spot of light as reflected from said object, two photoelectric effect elements, means for splitting said image into two images and directing said two images onto corresponding ones of said two photoelectric effect elements with said two images having apparent parallax except when said object is sharply in focus, and means responsive to output signals from said photoelectric effect elements departing from a given relationship for adjusting the focus of said lens until said object is sharply in focus.
Claim 2
Dependent Claim
118 words
An automatic focusing system for cameras comprising in combination means for projecting from a camera to an object a spot of light whose intensity is modulated, an adjustable focus lens for producing at said camera an image of said spot of light as reflected from said object, two photoelectric effect elements, means for splitting said image into two images and directing said two images onto corresponding ones of said two photoelectric effect elements with said two images having apparent parallax except when said object is sharply in focus, and means responsive to output signals from said photoelectric effect elements departing from a given relationship for adjusting the focus of said lens until said object is sharply in focus.
Claim 3
Dependent Claim
27 words
An automatic focusing system according to claim 1, wherein said camera has a separate picture taking lens interconnected with said adjustable focus lens for conjoint focusing adjustment.
Claim 4
Dependent Claim
38 words
An automatic focusing system according to claim 2, wherein said means for splitting said image into two images comprises an image magnifying relay lens and image splitting prisms disposed in the order mentioned behind said adjustable focus lens.
Claim 5
Dependent Claim
38 words
An automatic focusing system according to claim 1, wherein said means for splitting said image into two images comprises an image magnifying relay lens and image splitting prisms disposed in the order mentioned behind said adjustable focUs lens.
Claim 6
Dependent Claim
43 words
An automatic focusing system according to claim 4, wherein said means for splitting said image into two images further comprises a corresponding cylindrical lens and mask for defining the field of view interposed between said prisms and each of said photoelectric effect elements.
Claim 7
Dependent Claim
27 words
An automatic focusing system according to claim 5, wherein said camera has a separate picture taking lens interconnected with said adjustable focus lens for conjoint focusing adjustment.
Claim 8
Dependent Claim
45 words
An automatic focusing system according to claim 1, wherein means are provided for modulating said spot of light at a given frequency, and said means responsive to output signals from said photoelectric effect elements comprises filter means for passing signals only of said given frequency.
Claim 9
Dependent Claim
38 words
An automatic focusing system according to claim 7, wherein said means for splitting said image into two images comprises an image magnifying relay lens and image splitting prisms disposed in the order mentioned behind said adjustable focus lens.
Claim 10
Dependent Claim
43 words
An automatic focusing system according to claim 8, wherein said means for splitting said image into two images further comprises a corresponding cylindrical lens and mask for defining the field of view interposed between said prisms and each of said photoelectric effect elements.
Claim 11
Dependent Claim
27 words
An automatic focusing system according to claim 9, wherein said camera has a separate picture taking lens interconnected with said adjustable focus lens for conjoint focusing adjustment.
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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) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |