Camera film prewinding using D-shaped film perforations
AssigneeEastman Kodak Company
InventorsMichael DeCecca, Christopher Muir, Douglas Pearson, Ivan Thompson
Life of this patent
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Abstract
A film camera has a body enclosing a light-tight film space. A film unit disposed in the film space, includes a filmstrip having a longitudinally extending row of uniform perforations. The perforations each have at least one concavely-curved edge extending in a direction transverse to the filmstrip. The film space is substantially free of skives despite prewinding of the filmstrip in the camera, even if the prewinding is at a high-torque level.
Claims31
A film camera comprising:
- a body enclosing a light-tight film space;
- a film unit disposed in said film space, said film unit including a filmstrip having a longitudinally extending row of uniform perforations, said perforations each having at least one concavely-curved edge extending in a direction transverse to said filmstrip.
A film camera comprising:
- a body enclosing a light-tight film space;
- a film unit disposed in said film space, said film unit including a filmstrip having a longitudinally extending row of perforations, said perforations each having at least one concavely-curved edge extending in a direction transverse to said filmstrip;
- wherein said film space is substantially free of skives.
The film camera of claim 3 wherein said film space has a skive contamination rate of 0.04 or less.
A prewound film camera comprising:
- a body enclosing a light-tight film space, said body having first and second film chambers and an exposure frame disposed in said film space;
- an exposure system mounted in said body, said exposure system being operable to direct light through said exposure frame;
- a canister lodged in said first film chamber;
- a spool disposed in said canister;
- a filmstrip having a trailing end attached to said tape external to said canister, said filmstrip having a longitudinally extending sequence of perforations, said perforations each having at least one concavely-curved edge extending in a direction transverse to said filmstrip.
A filmstrip-film transport assembly comprising:
- a filmstrip having a longitudinally extending sequence of perforations, said perforations each having at least one concavely-curved edge extending in a direction transverse to said filmstrip;
- and
- a film transport actuable to advance said filmstrip, said film transport including at least one tooth having an engagement section engagable with said perforations, said engagement section having a different shape than said perforations.
A filmstrip-film transport assembly comprising:
- a filmstrip having a longitudinally extending sequence of perforations, said perforations each having a pair of opposed engagement edges, at least one of said pair of engagement edges being concavely-curved;
- and
- a film transport actuable to advance said filmstrip, said film transport including at least one tooth having an engagement portion engagable with said engagement edges, said engagement portion being straight.
A method for loading a film camera, the method comprising the steps of:
- lodging a canister of a film cartridge in the camera;
- attaching a leading end of a filmstrip of said film cartridge to a winder, said filmstrip having a longitudinally extending row of perforations, said perforations each having a pair of opposed engagement edges, at least one of said pair of engagement edges being concavely-curved;
- rotating said winder to withdraw at least a major portion of said filmstrip from said canister;
- and
- during said rotating turning a sprocket with said concavely-curved engagement edges.
A method for loading a film camera, the method comprising the steps of:
- lodging a canister of a film cartridge in the camera;
- attaching a leading end of a filmstrip of said film cartridge to a winder, said filmstrip having a longitudinally extending row of perforations, said perforations each having a pair of opposed engagement edges, at least one of said pair of engagement edges being concavely-curved;
- rotating said winder to withdraw at least a major portion of said filmstrip from said canister;
- advancing a frame of said filmstrip back into said canister;
- during at least one of said rotating and advancing steps, turning a sprocket with said concavely-curved engagement edges.
A collection of film units, each said film unit comprising:
- a filmstrip having a longitudinally extending row of perforations, said perforations each having at least one concavely-curved edge extending in a direction transverse to said filmstrip.
Dependencies are inferred from the claim text.