Patent US3820132A successfully refreshed from Google Patents.
US3820132A
Expired / Lapsed
US
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Exposure setting device in photographic apparatus
Assignee: Pentacon GmbH Foto und Feinwerktechnik
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Filing: 1973-05-14
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Granted: 1974-06-25
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Expires: 1993-05-14
Abstract
Abstract The device for setting exposures in photographic apparatus is provided with a light indicator by which the set exposure factor combination is indicated as corresponding to under-exposure, over exposure or the correct exposure. The indicator is provided with a luminous surface the light-dark egee of which is displaceable in dependence upon the brightness of the subject and the exposure factor combination set. The light-dark edge can be aligned from opposite directions with a linear or punctiform fixed mark which is arranged directly adjacent the luminous surface and along the range of movement of the light-dark edge.
Inventors
- 👤 F Lindner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:53
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/18; G03B17/20; G01; G01J; G01J1/00; G01J1/42; G01J1/44
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
151 words
An exposure setting device including a light sensitive detector influenced by prevailing light conditions, a control element connected in circuit with the light sensitive detector which control element is influenced by presetable exposure factors, an amplifier having an input connected with the light sensitive detector, an electro-luminescent diode having a control electrode connected with an output of the amplifier which electroluminescent diode has a display surface progressively illuminatable in dependance on the signal supplied to its control electrode to provide a displaceable illuminated area boundary, and a fixed index mark disposed adjacent the display wherein the mark is formed when the exposure setting device is connected with a source of suitable supply potential the position of the illuminated area boundary is influenced by the prevailing light conditions and the exposure factor combination and its position relative to the fixed index mark distinguishes between correct exposure, over exposure and under exposure setting.
Claim 2
Dependent Claim
151 words
An exposure setting device including a light sensitive detector influenced by prevailing light conditions, a control element connected in circuit with the light sensitive detector which control element is influenced by presetable exposure factors, an amplifier having an input connected with the light sensitive detector, an electro-luminescent diode having a control electrode connected with an output of the amplifier which electroluminescent diode has a display surface progressively illuminatable in dependance on the signal supplied to its control electrode to provide a displaceable illuminated area boundary, and a fixed index mark disposed adjacent the display wherein the mark is formed when the exposure setting device is connected with a source of suitable supply potential the position of the illuminated area boundary is influenced by the prevailing light conditions and the exposure factor combination and its position relative to the fixed index mark distinguishes between correct exposure, over exposure and under exposure setting.
Claim 3
Dependent Claim
23 words
An exposure setting device according to claim 1, wherein the fixed index mark comprises a slit illuminated by an auxilliary source of light.
Claim 4
Dependent Claim
52 words
In a photographic camera having a viewfinder provided with a mask defining the picture area, the provision of an exposure setting device according to claim 1 wherein the fixed index mark is formed by an opening in the mask which opening is illuminated by light emanating from the subject to be photographed.
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) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |