US3599547A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic apparatus with automatic exposure control means
Assignee: Agfa Gevaert AG
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Filing: 1969-05-27
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Granted: 1971-08-17
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Expires: 1989-05-27
Abstract
Abstract A photographic apparatus wherein the needle of the light meter is movable between first and second ranges of positions which respectively indicate higher and lower scene brightnesses. A detector which is movable into engagement with the needles in response to actuation of the camera release selects the size of the diaphragm aperture as a function of a higher scene brightness and selects a constant medium aperture size when the brightness of the scene is low. The exposure time is selected as a function of scene brightness; however, the rate at which the exposure time changes when the needle moves within the first range of positions is different from the rate at which the exposure time changes when the needle moves within the second range of positions, i.e., when the aperture size remains constant.
Inventors
- 👤 Karl Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:43
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/12
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
185 words
In a photographic apparatus, a combination comprising light meter means having an output member movable between first and second ranges of positions which are respectively indicative of higher and lower scene brightnesses; detector means movable into engagement with said output member to thereby select one of a series of aperture sizes when said output member assumes one of saiD first range of positions and to select a predetermined aperture size when the output member assumes one of said second range of positions, said series of aperture sizes including a maximum and a minimum aperture size and said predetermined size being smaller than said maximum size but larger than said minimum size; adjustable shutter-setting means operative to set the shutter and to thereby select the exposure time as a function of scene brightness; and control means for adjusting said shuttersetting means as a function of said predetermined aperture size when said output member assumes one of said second range of positions so that the exposure time which is set by the shutter is a function of scene brightness and a function of said predetermined aperture size.
Claim 2
Dependent Claim
185 words
In a photographic apparatus, a combination comprising light meter means having an output member movable between first and second ranges of positions which are respectively indicative of higher and lower scene brightnesses; detector means movable into engagement with said output member to thereby select one of a series of aperture sizes when said output member assumes one of saiD first range of positions and to select a predetermined aperture size when the output member assumes one of said second range of positions, said series of aperture sizes including a maximum and a minimum aperture size and said predetermined size being smaller than said maximum size but larger than said minimum size; adjustable shutter-setting means operative to set the shutter and to thereby select the exposure time as a function of scene brightness; and control means for adjusting said shuttersetting means as a function of said predetermined aperture size when said output member assumes one of said second range of positions so that the exposure time which is set by the shutter is a function of scene brightness and a function of said predetermined aperture size.
Claim 3
Dependent Claim
103 words
A combination as defined in claim 1, wherein said control means comprises an R-C link having a capacitor and a resistance including said light meter means and variable resistor means having a movable portion and a second portion, said second portion of said variable resistor means constituting a back support which is contacted by said output member when the latter assumes one of said first range of positions and is engaged by said detector means, said back support and said output member consisting at least in part of current-conducting material and said output member constituting the movable portion of said variable resistor means.
Claim 4
Dependent Claim
46 words
A combination as defined in claim 1, wherein said control means comprises an R-C link including said light meter means, corrective resistor means, and disconnecting means for disconnecting said resistor means from said link when said output member assumes one of said second range of positions.
Claim 5
Dependent Claim
40 words
A combination as defined in claim 3, wherein said disconnecting means includes a switch which is actuated in response to engagement of said detector means with said output member while the latter assumes one of said second range of positions.
Claim 6
Dependent Claim
44 words
A combination as defined in claim 3, wherein said link includes capacitor means and a composite resistance which includes said light meter means, and further comprising switch means for connecting said composite resistance with said capacitor means in each position of said output member
Claim 7
Dependent Claim
51 words
A combination as defined in claim 3, wherein said link includes capacitor means and a composite resistance which includes said light meter means, and further comprising switch means for connecting said composite resistance with said capacitor means at least when said output member assumes one of said second range of positions.
Claim 8
Dependent Claim
48 words
A combination as defined in claim 1 , further comprising an exposure control circuit which includes said light meter means and further includes photosensitive receiver means exposed to scene light, at least one corrective resistor and switch means operative to connect and disconnect said resistor from said circuit.
Claim 9
Dependent Claim
35 words
A combination as defined in claim 1, further comprising release means movable from a starting position and switch means responsive to movement of said release means from starting position to thereby actuate said control means.
Claim 10
Dependent Claim
15 words
A combination as defined in claim 1, wherein said control means includes said output member.
Claim 11
Dependent Claim
16 words
A combination as defined in claim 9, wherein said control means further includes said detector means.
Claim 12
Dependent Claim
52 words
A combination as defined in claim 1, further comprising a back support which is engaged by said output member when the latter assumes one of said first range of positions and is engaged by said detector means, said control means including an R-C link having a resistance which includes said back support.
References Cited (Backward Citations)
US3433140A
Cited
US3500731A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-16 | 1975-02-15 | 1975-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-16 | 1979-02-15 | 1979-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-16 | 1983-02-15 | 1983-08-17 | $7700.00 | Window Closed / Lapsed |