US3695158A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic camera
Assignee: Compur Werk GmbH and Co
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Filing: 1970-07-22
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Granted: 1972-10-03
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Expires: 1990-07-22
Abstract
Abstract A photographic camera in which one of the two factors of diaphragm aperture and shutter speed is manually presettable, and the other of the two factors is automatically set by electrical mechanism dependent in part on the value of the preset factor and in part on the brightness of the subject to be photographed, which is measured by a photoresistance. A balancing bridge circuit is used, one branch of which contains the photoresistance, another branch of which contains a resistance element and a sliding wiper element, each of these elements being separately movable relative to the other element. A first motor, controlled in part by the value of the presettable factor, moves the resistance element relative to the wiper element. A second motor, controlled by the balancing bridge circuit, moves the wiper element relative to the resistance element until the bridge is in balance. The movement of this second motor also sets automatically the value of the other exposure factor.
Inventors
- 👤 Paul Fahlenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:58
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/083
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
226 words
A photographic camera having settable factors of diaphragm aperture and shutter speed to be set for making an exposure, one of said factors being presettable by the photographer, the other of said factors being settable automatically, said camera comprising a setting member (30) movable to preset the presettable one of said factors, an electric circuit forming a balancing bridge system having a group of balancing resistances in which said settable factors may be stored, said balancing resistances including a photoresistance (70) responsive to the brightness of a subject to be photographed and a resistance (66) associated with the factor which is preset, a sliding wiper (68) cooperating with said last mentioned resistance and constituting part of said bridge system, two switch contacts (50a, 50b) and a switch member (44) movable into engagement with either one of said contacts, a movable holder (46) on which said contacts and switch member are mounted, a movable carrier (63) for said resistance, a source of current (67), a motor (64) driven from said source of current under control of said contacts, means (30a, 42) controlled by said setting for moving said switch member, and transmission means (61, 62, 65) operated by said motor for moving said holder, to vary the relation thereof to said setting member, and for moving said carrier, to vary the relation thereof to said sliding wiper.
Claim 2
Dependent Claim
226 words
A photographic camera having settable factors of diaphragm aperture and shutter speed to be set for making an exposure, one of said factors being presettable by the photographer, the other of said factors being settable automatically, said camera comprising a setting member (30) movable to preset the presettable one of said factors, an electric circuit forming a balancing bridge system having a group of balancing resistances in which said settable factors may be stored, said balancing resistances including a photoresistance (70) responsive to the brightness of a subject to be photographed and a resistance (66) associated with the factor which is preset, a sliding wiper (68) cooperating with said last mentioned resistance and constituting part of said bridge system, two switch contacts (50a, 50b) and a switch member (44) movable into engagement with either one of said contacts, a movable holder (46) on which said contacts and switch member are mounted, a movable carrier (63) for said resistance, a source of current (67), a motor (64) driven from said source of current under control of said contacts, means (30a, 42) controlled by said setting for moving said switch member, and transmission means (61, 62, 65) operated by said motor for moving said holder, to vary the relation thereof to said setting member, and for moving said carrier, to vary the relation thereof to said sliding wiper.
Claim 3
Dependent Claim
59 words
A camera as defined in claim 1, wherein said camera has an optical axis, and wherein said means controlled by the setting member for moving said switch member includes a setting pin (42) displaceable in a direction parallel to said optical axis, and wherein said movable holder (46) is also movable in a direction parallel to said optical axis.
Claim 4
Dependent Claim
82 words
A camera as defined in claim 2, further comprising a slide (56) movable in a direction parallel to said optical axis, a releasable coupling for coupling said slide to said holder in a plurality of positions of adjustment, and a film sensitivity scale (58) for indicating the position of adjustment of said slide relative to said holder, said transmission means acting on said slide to move it and thereby to move said holder through the coupling of said slide to said holder.
Claim 5
Dependent Claim
36 words
A camera as defined in claim 1, further comprising a second motor (82), and a rotary plate (88) driven by said second motor, said sliding wiper (68) being mounted on and moving with said rotary plate.
Claim 6
Dependent Claim
32 words
A camera as defined in claim 4, wherein said second motor is driven from a source of current (84) through an amplifier (80) connected to and controlled by said balancing bridge system.
Claim 7
Dependent Claim
63 words
A camera as defined in claim 4, further comprising electric circuit means for determining said automatically settable photographic factor, said circuit means including a second resistance (92) and a second sliding wiper (90) movable over said second resistance to vary the effective resistance thereof in said circuit means, said second sliding wiper (90) being mounted on and moving with said rotary plate (88).
Claim 8
Dependent Claim
35 words
A camera as defined in claim 6, further comprising a scale (142) graduated in terms of shutter speed, and a marker (90a) carried by said second sliding wiper (90) for cooperation with said scale (142).
Claim 9
Dependent Claim
58 words
A camera as defined in claim 1, further comprising electric circuit means for determining said automatically settable photographic factor as a result of the setting of said presettable factor and the brightness of the subject as influencing said photoresistance, and a scale for indicating a value of said automatically settable factor as determined by said electric circuit means.
Claim 10
Dependent Claim
33 words
A camera as defined in claim 1, wherein said presettable factor is the factor of diaphragm aperture and is manually settable, and wherein said factor settable automatically is the factor of shutter speed.
Claim 11
Dependent Claim
209 words
A photographic camera having settable factors of diaphragm apErture and shutter speed to be set for making an exposure, one of said exposure factors being presettable by the photographer, the other of said exposure factors being settable automatically, said camera comprising a setting member movable to set the presettable factor, means forming a balancing bridge circuit including a first branch and a second branch, said first branch including a photo-resistance responsive to the brightness of a subject to be photographed, said second branch including a resistance element and a sliding wiper contacting therewith in various positions to vary the effective resistance of said element in said second branch, a first motor for moving said resistance element relative to a given position of said sliding wiper, means controlled by said setting member of the presettable factor for operating said first motor, a second motor for moving said sliding wiper relative to a given position of said resistance element, means responsive to relative resistance characteristics of said first branch and said second branch for operating said second motor to move said sliding wiper until a balance is achieved in said bridge circuit, and means responsive to operation of said second motor for setting the automatically settable one of said exposure factors.
Claim 12
Dependent Claim
209 words
A photographic camera having settable factors of diaphragm apErture and shutter speed to be set for making an exposure, one of said exposure factors being presettable by the photographer, the other of said exposure factors being settable automatically, said camera comprising a setting member movable to set the presettable factor, means forming a balancing bridge circuit including a first branch and a second branch, said first branch including a photo-resistance responsive to the brightness of a subject to be photographed, said second branch including a resistance element and a sliding wiper contacting therewith in various positions to vary the effective resistance of said element in said second branch, a first motor for moving said resistance element relative to a given position of said sliding wiper, means controlled by said setting member of the presettable factor for operating said first motor, a second motor for moving said sliding wiper relative to a given position of said resistance element, means responsive to relative resistance characteristics of said first branch and said second branch for operating said second motor to move said sliding wiper until a balance is achieved in said bridge circuit, and means responsive to operation of said second motor for setting the automatically settable one of said exposure factors.
Claim 13
Dependent Claim
170 words
A camera as defined in claim 10, further comprising visible indicating means for visually indicating the value of the automatically settable exposure factor which has been set upon operation of said second motor, electric current means for furnishing power to both of said motors, first switch means no normally open and closable to connect said current means operatively to said motors, second switch means normally open and closable to initiate a photographic exposure cycle, and a camera trip member manually movable when a photograph is to be taken, said trip member being effective at an intermediate point of its full range of travel to close said first switch means without closing said second switch means, so that said motors may be operated and the value of the automatically settable exposure may be visually observed without initiating an exposure cycle, said trip member upon further movement beyond said intermediate point to its full range limit being effective to close said second switch means also, so that an exposure cycle is initiated.
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) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |