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US3604329A Expired / Lapsed US ⏱️ 0.0 years remaining

Photographic apparatus and process for controlling the development of individual film units as a function of temperature

Assignee: Polaroid Corp
•
Filing: 1969-11-20
•
Granted: 1971-09-14
•
Expires: 1989-11-20
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Abstract

Abstract A camera and a photographic process performed therein in which a viscous photographic processing liquid is distributed in a thin layer between an exposed photosensitive element and another element by moving the elements in superposition through a convergent passage between a pair of juxtaposed pressure-applying members biased toward one another by a substantially constant force. The viscosity of the liquid varies inversely with temperature and the speed of movement of the elements is varied in direct relation to the ambient temperature to insure uniform liquid distribution despite temperature changes. The thickness of the layer of liquid can also be maintained constant despite changes in temperature and viscosity by varying the pressure exerted on the elements by the pressure-applying members, and the camera includes structure for varying the pressure exerted by the pressure-applying members as a function of temperature.

Inventors

  • 👤 Edwin H Land

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 00:47
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/48; G03B17/50; G03B17/52

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 24 words
Photographic processing apparatus as defined in claim 1 wherein said biasing means urge said pressure members toward one another with a substantially constant force.
Claim 2
Dependent Claim 18 words
Photographic processing apparatus as defined in claim 2 wherein said biasing means include relatively low rate spring means.
Claim 3
Dependent Claim 37 words
Photographic processing apparatus as defined in claim 1 wherein said advancement means include a drive motor and said control means include means for varying the speed of said drive motor in direct relation to the ambient temperature.
Claim 4
Dependent Claim 72 words
Photographic processing apparatus as defined in claim 3 wherein said members comprise a pair of rolls mounted for rotation with their axes in a common plane, said advancement means include drive means for rotating said rolls in engagement with said superposed elements located between said rolls and said control means are coupled with said drive means for varying the speed of rotation of said rolls in direct relation to the ambient temperature.
Claim 5
Dependent Claim 131 words
In a photographic process in which a viscous liquid processing agent is distributed in a thin layer between an exposed photosensitive element and another element superposed therewith, the combination of steps including: moving said elements in superposition through a convergent passage between a pair of juxtaposed pressure-applying members to distribute a viscous liquid agent having a viscosity which varies with temperature, in a thin layer between said elements; during movement of said elements between said members, biasing members towards one another into compressive engagement with said elements with a controlled force; and varying the speed of movement of said elements in direct relation to the ambient temperature to compensate for temperature-related changes in the viscosity of said liquid agent and thereby distribute said liquid agent in a layer of predetermined thickness.
Claim 6
Dependent Claim 20 words
In a photographic process as defined in claim 6, biasing said members toward one another with a substantially constant force.
Claim 7
Dependent Claim 41 words
A photographic process as defined in claim 6 wherein at least one of said elements is a flexible sheet and compressive pressure is applied to said elements substantially along a line extending transverse to the direction of movement of said elements.
Claim 8
Dependent Claim 20 words
A photographic process as defined in claim 6 wherein said liquid processing agent includes water and a polymeric thickening agent.
Claim 9
Dependent Claim 33 words
A photographic process as defined in claim 9 wherein said liquid processing agent is thixotropic and said elements are moved at a speed within a range such that said processing agent exhibits thixotrophy.

References Cited (Backward Citations)

US2854905A Cited
US3447437A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1974-09-13 1975-03-15 1975-09-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1978-09-13 1979-03-15 1979-09-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1982-09-13 1983-03-15 1983-09-14 $7700.00 Window Closed / Lapsed

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