Patent US2008965A successfully refreshed from Google Patents.
US3733989A
Expired / Lapsed
US
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Automatic focusing arrangement
Assignee: Agfa Gevaert AG
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Filing: 1971-12-23
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Granted: 1973-05-22
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Expires: 1991-12-23
Abstract
Abstract A split image of a vertical edge of an object is formed by a standard range finder, the two half images coinciding in a vertical direction when the objective lens is properly focused. An oscillating mirror reflects light along a horizontal line including the top half image onto a first photocell and light along a horizontal line including the bottom half image onto a second photo-cell. The photocells thus emit a scanning signal when the respective half images are reflected thereon. A first and a second threshold circuit is responsive to these scanning signals and the outputs of the first and second threshold circuit are applied each to one input of and AND-gate, the output of which causes the motor positioning the objective lens to stop upon simultaneous receipt of the scanning signals.
Inventors
- 👤 R Wick
- 👤 A Winkler
- 👤 Fischern B Von
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:16
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/30; G02B7/305
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
214 words
In a photographic camera, an automatic focusing arrangement, comprising, in combination, lens means; moving means moving said lens means along a predetermined path between a first and second end position; optical means creating a split image of a determined portion of an object to be photographed, said split image comprising a first and second half image displaced from each other along a first axis when said lens means is incorrectly positioned for focusing said object and coinciding when said lens means is correctly positioned for focusing said object; oscillating mirror means mounted to reflect said first and second half image, respectively, back and forth along a first and second predetermined path parallel to said predetermined axis; first and second photosensitive means respectively mounted in corresponding positions along said first and second predetermined path for receiving said so-reflected first and second half images respectively and furnishing a first and second scanning signal, respectively, in response thereto; and AND-gate means having a first and second input respectively connected to said first and second photosensitive means and an AND-gate output connected to said moving means, foR deenergizing said moving means in response to simultaneous receipt of said first and second scanning signals, whereby said moving means are stopped upon alignment of said first and second half image.
Claim 2
Dependent Claim
214 words
In a photographic camera, an automatic focusing arrangement, comprising, in combination, lens means; moving means moving said lens means along a predetermined path between a first and second end position; optical means creating a split image of a determined portion of an object to be photographed, said split image comprising a first and second half image displaced from each other along a first axis when said lens means is incorrectly positioned for focusing said object and coinciding when said lens means is correctly positioned for focusing said object; oscillating mirror means mounted to reflect said first and second half image, respectively, back and forth along a first and second predetermined path parallel to said predetermined axis; first and second photosensitive means respectively mounted in corresponding positions along said first and second predetermined path for receiving said so-reflected first and second half images respectively and furnishing a first and second scanning signal, respectively, in response thereto; and AND-gate means having a first and second input respectively connected to said first and second photosensitive means and an AND-gate output connected to said moving means, foR deenergizing said moving means in response to simultaneous receipt of said first and second scanning signals, whereby said moving means are stopped upon alignment of said first and second half image.
Claim 3
Dependent Claim
66 words
An arrangement as set forth in claim 1, further comprising first diaphragm means positioned between said oscillating mirror means and said first and second photosensitive means, said first diaphragm means having a first and second slit extending parallel to said predetermined axis said slit allowing transmittal of a selected portion of said reflected first and second half image to said first and second photosensitive means, respectively.
Claim 4
Dependent Claim
43 words
An arrangement as set forth in claim 2, further comprising second diaphragm means arranged between said optical means and said oscillating mirror means, said second diaphragm means having a first horizontal slit, and a second horizontal slit arranged below said first horizontal slit.
Claim 5
Dependent Claim
46 words
An arrangement as set forth in claim 3, wherein said oscillating mirror means have an angle of oscillation smaller than the angle of oscillation required for transmitting light along the full length of said first and second horizontal strip onto said first and second photosensitive means.
Claim 6
Dependent Claim
29 words
An arrangement as set forth in claim 2, wherein said first diaphragm means have a first horizontal slit, and a second horizontal slit arranged below said first horizontal slit.
Claim 7
Dependent Claim
43 words
An arrangement as set forth in claim 1, wherein said moving means comprise servomotor means; further comprising switching circuit means connected to said AND-gate output for deenergizing said servomotor means in response to substantially simultaneous receipt of said first and second scanning signals.
Claim 8
Dependent Claim
37 words
An arrangement as set forth in claim 6, further comprising first and second pulse-forming means respectively interconnected between said first photosensitive means and said first AND-gate input, and said second photosensitive means and said second AND-gate input.
Claim 9
Dependent Claim
24 words
An arrangement as set forth in claim 7, wherein said first and second pulse-forming means each comprise amplifier means, differentiating means, and rectifier means.
Claim 10
Dependent Claim
33 words
An arrangement as set forth in claim 8, further comprising first and second Schmitt trigger means interconnected between said amplifier means and said differentiation means of said first and second pulse-forming means respectively.
Claim 11
Dependent Claim
35 words
An arrangement as set forth in claim 9, wherein said first and second pulse-forming means respectively comprise first and second emitter-follower means connected between said rectifier means and said first and second AND-gate input respectively.
Claim 12
Dependent Claim
70 words
An arrangement as set forth in claim 10, wherein said first and second emitter-follower means comprise a first and second transistor respectively; and further comprising first and second biasing means respectively biasing said first and second transistor means to cut-off in the absence of said first and second scanning signal respectively; and wherein said first and second scanning signal respectively drive said first and second transistor to a conductive condition.
Claim 13
Dependent Claim
47 words
An arrangement as set forth in claim 11, wherein said switching circuit means comprise thyristor means having a gate connected to said AND-gate output; and switching transistor means having a base connected to the anode of said thyristor means and an emitter-collector circuit connected to said servomotor.
Claim 14
Dependent Claim
15 words
An arrangement as set forth in claim 1, wherein said photosensitive means comprise photovoltaic cells.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |