US4175843A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Duel focal plane photocells
Assignee: Polaroid Corp
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Filing: 1978-04-04
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Granted: 1979-11-27
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Expires: 1998-04-04
Abstract
Abstract A camera having a pair of spaced lenses for sequentially exposing successive adjacent portions of the same light sensitive surface of a film unit. A pair of opaque doors, each having a photocell thereon, are pivotally mounted in overlying relation to the adjacent portions of the film unit and directly in front of the focal plane of the lenses. The doors are mounted for simultaneous movement between a first position wherein one of the doors and its associated photocell is located beyond the light path between one of the lenses and one of the adjacent portions of the film unit while the other door and its associated photocell overlies the other portion of the film unit so as to prevent exposure thereof, and a second position wherein the one door overlies the one portion of the film unit so as to prevent exposure thereof and the other door is located beyond the light path between the other of the two lenses and the other portion of the film unit. The doors are coupled to a shutter release button such that depression of the button, when the doors are in the first position, results in initiating exposure of the one portion of the film unit to light passing through one of the lenses while the other photocell responds to the light passing through the other lens to control the exposure; and release of the shutter button results in the doors moving into the second position in preparation for the exposure of the other portion of the film unit to light passing through the other lens, which exposure will be controlled in accordance with the intensity of the light passing through the one lens and striking the one photocell.
Inventors
- 👤 Lawrence M. Douglas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:20
CPC Classifications
G; G03; G03B; G03B19/00; G03B19/02; G03B19/023; G03B17/00; G03B17/02; G03B17/04; G03B7/00; G03B7/08; G03B7/099; G03B7/0993
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
396 words
A camera for exposing successive portions of the same light sensitive surface of a film unit comprising: means for exposing successive portions of a film unit including first and second objective lenses having parallel optical axes; means for supporting a film cassette containing at least one film unit within the camera such that adjacent first and second portions of the film unit are located in alignment with and in the focal plane of said first and second lenses, respectively, during exposure of the film unit; first and second photocells for responding to the light intensity and for participating in the determination of the extent to which the adjacent portions of the film unit are exposed; first and second opaque means for alternatively supporting said first and second photocells directly in front of said focal plane such that the intensity of the light reaching said first and second photocells closely approximates the intensity of the light to which the second and first adjacent portions of the film unit, respectively, are subsequently exposed to, said first photocell being positionable between the first portion of the film unit and said first lens, and said second photocell being positionable between the second portion of the film unit and said second lens; means for moving said first and second opaque supporting means between a first position, wherein said second opaque supporting means overlies the second portion of the film unit so as to prevent exposure thereof and said first opaque supporting means is located beyond the light path between said first lens and the first portion of the film unit, and a second position wherein said first opaque supporting means overlies the first portion of the film unit so as to prevent exposure thereof and said second opaque supporting means is located beyond the light path between said second lens and the second portion of the film unit; and means for initiating an exposure cycle so as to allow the passage of scene light into the camera by way of said first and second lenses whereby when said first and second opaque supporting means are located in said first position the light passing through said first lens exposes the first portion of the film unit and the light passing through the second lens strikes said second photocell so as to control the exposure of the first portion of the film unit.
Claim 2
Dependent Claim
396 words
A camera for exposing successive portions of the same light sensitive surface of a film unit comprising: means for exposing successive portions of a film unit including first and second objective lenses having parallel optical axes; means for supporting a film cassette containing at least one film unit within the camera such that adjacent first and second portions of the film unit are located in alignment with and in the focal plane of said first and second lenses, respectively, during exposure of the film unit; first and second photocells for responding to the light intensity and for participating in the determination of the extent to which the adjacent portions of the film unit are exposed; first and second opaque means for alternatively supporting said first and second photocells directly in front of said focal plane such that the intensity of the light reaching said first and second photocells closely approximates the intensity of the light to which the second and first adjacent portions of the film unit, respectively, are subsequently exposed to, said first photocell being positionable between the first portion of the film unit and said first lens, and said second photocell being positionable between the second portion of the film unit and said second lens; means for moving said first and second opaque supporting means between a first position, wherein said second opaque supporting means overlies the second portion of the film unit so as to prevent exposure thereof and said first opaque supporting means is located beyond the light path between said first lens and the first portion of the film unit, and a second position wherein said first opaque supporting means overlies the first portion of the film unit so as to prevent exposure thereof and said second opaque supporting means is located beyond the light path between said second lens and the second portion of the film unit; and means for initiating an exposure cycle so as to allow the passage of scene light into the camera by way of said first and second lenses whereby when said first and second opaque supporting means are located in said first position the light passing through said first lens exposes the first portion of the film unit and the light passing through the second lens strikes said second photocell so as to control the exposure of the first portion of the film unit.
Claim 3
Dependent Claim
49 words
A camera as defined in claim 1 further including means for coupling said exposure initiating means to said moving means for actuating the latter in response to the actuation of said exposure initiating means to move said first and second opaque supporting means between said first and second positions.
Claim 4
Dependent Claim
44 words
A camera as defined in claim 2 further including means for resiliently biasing said first and second opaque supporting means toward each other such that the first and second opaque supporting means define an obtuse angle therebetween when in said first or second positions.
Claim 5
Dependent Claim
97 words
A camera as defined in claim 3 wherein said camera is comprised of a plurality of housing sections coupled to each other for movement between an operative extended position and an inoperative collapsed position, one of said housing sections including means movable into engagement with one of said first and second opaque supporting means during movement of said housing sections toward said inoperative collapsed position for moving said one opaque supporting means against the force of said biasing means into the same plane as that occupied by the other of said first and second opaque supporting means.
Claim 6
Dependent Claim
55 words
A camera as defined in claim 1 wherein each of said first and second photocells includes a plurality of louvers for preventing light from directly striking the face of the photocell when it is located out of the path of light between its associated lens and the portion of the film unit to be exposed.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-26 | 1983-05-28 | 1983-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-26 | 1987-05-28 | 1987-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-26 | 1991-05-28 | 1991-11-27 | $7700.00 | Window Closed / Lapsed |