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US3800684A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control device for an exposure meter for photographic cameras
Assignee: Victor Hasselblad AB
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Filing: 1972-02-24
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Granted: 1974-04-02
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Expires: 1992-02-24
Abstract
Abstract This invention relates to photographic cameras provided with a through-the-lens exposure meter adapted for both automatic and manual measurement, in which a differential means in the exposure meter is actuated by a rotational movement, and a rheostat in the exposure meter is set for a resistance value proportional to the total of the correction values of two exposure factors. The invention, more precisely, relates to a control device for actuation of the exposure meter, combined with means, which upon manual measurement simulate the angle of rotation for adjusting the rheostat, which angle upon automatic measurement is adjusted by the mechanical differential included in the exposure meter. The control device is designed as a so-called control box, which is mounted on the camera exterior and is provided with a control key for actuating the exposure meter and with two knobs having setting scales with indexes for automatic measurement and, respectively, for occurring values of the two exposure factors, the latter used in manual measurement.
Inventors
- 👤 L Johansson
- 👤 L Tenne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:58
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/02; G03B7/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
191 words
In a through-the-lens exposure control system for a camera, the combination comprising: means for controling the exposure of film in the camera, a rotary mechanical differential for responsive to Indicia indicative of a plurality of exposure factors, said means for controling having a circuit including a component setable in accordance with said exposure factors, a control device operatively connectable to said differential for setting controling means, control means for selectively manually actuating said control device to a first condition corresponding to automatic operation of said exposure meter in which condition said differential is operatively connected to said control device for setting said component in accordance with said indicia, said control means being also effective to selectively manually actuate said control device to a second condition corresponding to manual operation of said exposure controling means, where said differential is disengaged from said indicia, and manually operable input means governed in accordanCe with a predetermined plurality of manually applied exposure factors and effective on said control device in its said second condition to set said variable circuit parameter to a particular value representative of the combination of said manually set exposure factor manifestations.
Claim 2
Dependent Claim
191 words
In a through-the-lens exposure control system for a camera, the combination comprising: means for controling the exposure of film in the camera, a rotary mechanical differential for responsive to Indicia indicative of a plurality of exposure factors, said means for controling having a circuit including a component setable in accordance with said exposure factors, a control device operatively connectable to said differential for setting controling means, control means for selectively manually actuating said control device to a first condition corresponding to automatic operation of said exposure meter in which condition said differential is operatively connected to said control device for setting said component in accordance with said indicia, said control means being also effective to selectively manually actuate said control device to a second condition corresponding to manual operation of said exposure controling means, where said differential is disengaged from said indicia, and manually operable input means governed in accordanCe with a predetermined plurality of manually applied exposure factors and effective on said control device in its said second condition to set said variable circuit parameter to a particular value representative of the combination of said manually set exposure factor manifestations.
Claim 3
Dependent Claim
37 words
The improvement of claim 1 wherein said control device comprises a housing secured to the exterior of the camera case, said device comprising rotary means having an axle operatively coupled to the axle of the rotary differential.
Claim 4
Dependent Claim
80 words
The improvement of claim 1 which further includes a manually operable control key projecting outwardly of said housing, linkage means operatively coupled with said control key, a toothed sector element, an axle operatively connected to the rotary mechanical differential, a cogwheel supported on said axle and meshing with said toothed sector, spring means responsive to said linkage means for rotating said axle through said toothed sector and said cogwheel as said control key is actuated to thereby operate said differential.
Claim 5
Dependent Claim
151 words
The improvement of claim 3 which further includes an adjustable stop means mounted on said axle and constituting a fixed stop member, and an adjustable stop pin operable to a first position when said control device is in its said first condition to permit operation of said differential through its entire operating range in response to actuation of said control key and only as limited by the inputs to said differential, said control device when in its said second condition operating said adjustable stop pin to a particular position in a predetermined range of its movement as selected by said manually set exposure factors manifestations, said adjustable stop pin in its said particular position limiting movement of said fixed stop to a corresponding predetermined position as said axle is rotated in response to actuation of said control key to thereby set said component in accordance with said manually set exposure factors.
Claim 6
Dependent Claim
24 words
The improvement of claim 4 wherein said control means comprises two independently rotatable setting members having associated scales for setting said adjustable stop pin.
Claim 7
Dependent Claim
63 words
The improvement of claim 4 wherein said stop pin is mounted on a ratchet wheel having a toothed position engaging a resilient catch means, said device further including a shield member defining a groove which slidably receives said stop pin, said groove limiting the extent of movement of the stop pin to a value corresponding to the measuring range of the exposure meter.
References Cited (Backward Citations)
US3481259A
Cited
US3601024A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |