Method and apparatus for heating cassette contained film strip during processing
AssigneePolaroid Corporation
InventorEdwin H. Land
Life of this patent
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Abstract
A film strip heating method and apparatus for use in photographic systems of the type in which a film strip, contained in a multi-purpose cassette during exposure, processing and projection, is processed by insertion of the cassette in a viewer operative to release a cassette-contained supply of processing fluid, and in which localized heating of the film strip is effected during the processing operation to enhance the diffusion transfer developing process. Heating and temperature sensing components located in the cassette are connected with a control circuit in the viewer automatically upon insertion of the cassette in the viewer.
Claims10
A photographic cassette comprising:
- a housing having an opening therein;
- an initially unexposed elongated film strip;
- film advance means when driven for progressively advancing said film strip within said housing to traverse said opening, said film advance means being initially operative to facilitate the recording of a series of latent images along said film strip;
- means for applying a processing fluid to progressive incremental sections of said film strip to develop said film strip after exposure thereof and as said film strip is progressively advanced along a predetermined path past said applying means whereby substantially the entire length of said film strip is coated with the processing fluid;
- an electrical heating element positioned within said housing so as to increase the temperature of the processing fluid;
- electrical contacts mounted on said housing to be accessible to an external source of electrical energy;
- and
- means for electrically coupling said electrical contacts with said heating element, whereby said heating element is selectively energizable by such an externally mounted source of electrical energy.
A photographic system comprising:
- a film cassette including:
- a cassette housing;
- an elongated strip of exposed unprocessed film retained within said cassette housing;
- a processing fluid applicator within said housing, said applicator including means actuatable for applying processing fluid to progressive incremental sections of said film strip to develop said film strip as said film strip is advanced along a predetermined path traversing said applicator;
- externally accesible film advance means when driven for advancing said film strip along said predetermined path within said cassette housing to traverse said fluid applicator;
- an electrical heating element mounted within said cassette housing in close proximity to said predetermined film path and to said processing fluid applicator, said heating element being energizeable to increase the temperature of said processing fluid;
- and
- an apparatus including:
- means for receiving said film cassette;
- means for actuating said fluid applicator and for driving said film advance means when said cassette is positioned in said receiving means;
- and
- switch means for electrically coupling said cassette electrical contacts to a source of electrical energy when said cassette is positioned in said receiving means.
The system of claim 18 wherein said heating element is located within said cassette housing adjacent said predetermined path to apply heat to incremental sections of said film strip during film strip travel thereby increasing the temperature of the fluid applied thereto.
Photographic apparatus comprising:
- means for receiving a film cassette containing an elongated strip of exposed, undeveloped film, film advance means when driven for advancing said film strip along a predetermined path within said cassette, a processing fluid applicator actuatable responsive to advancement of said film strip for applying a coating of processing fluid to said film strip to develop said film strip, a heating element energizeable to increase the temperature of said processing fluid, and externally accessible contacts electrically coupled to said heating element;
- selectively operative means for driving said film advance means;
- switch means actuatable for coupling said contacts to an electrical source to heat said element;
- and
- means for controlling said switch means and said driving means to energize said heating element and initially drive said film advance means to actuate said fluid applicator, then halt said driving of said film advance means for an interval during which said element is raised to its operating temperature, and subsequently again drive said film advance means to apply a coating of said fluid to substantially the full extent of said film strip.
Dependencies are inferred from the claim text.