Dual sprocket contact motion picture film printer
AssigneeManfred G. Michelson
InventorsManfred G. Michelson, Markus G. Michelson
Life of this patent
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Abstract
A dual sprocket contact motion picture film printer maintains film steadiness when running a film negative in contact with an unexposed raw stock film by tensioning perforations along one film side against sprocket teeth of a full fitting sprocket and a shrinkage sprocket on the other side. The films pass through a fluid chamber before passing through a printer aperture and a vacuum pressure applied from one side of the chamber tensions the negative against the sprocket teeth while a positive fluid pressure applied from an opposite side tensions the raw stock against the sprocket. The films are self-aligned by the fluid forces maintaining equal tension on both sides of each film strip as the films pass the aperture of the film printer.
Claims15
A method of feeding a film negative and a raw stock film onto a dual sprocket of a film printer which feeds the negative and the raw stock to an aperture for exposing the negative and the raw stock to a light source as the dual sprocket rotates to move the negative and the raw stock past the aperture, both the negative and the raw stock having a left side with a left set of perforations, a right side with a right set of perforations, an emulsion side and a cell side, the negative and the raw stock being fed so that the emulsion sides are facing each other, the dual sprocket having a full fitting sprocket and a shrinkage sprocket, comprising the steps of:
- feeding the negative and the raw stack into a chamber;
- applying a first pressure in the chamber to cell side of the negative;
- applying a second pressure in the chamber to the cell side of the stock;
- and
- feeding the negative and the raw stock from the chamber to the dual sprocket;
- wherein the negative and the stock are deflected in the same direction in the chamber;
- and
- wherein the first and the second pressure cause both the left and the right set of perforations of the negative and the raw stock to contact teeth of the dual sprocket under tension.
A contact film printer having a sprocket for engaging spaced-apart perforations along both sides of a film entering the printer, the printer having an aperture for exposing overlapping films to light as the sprocket rotates to move the films past the aperture, and a fluid chamber positioned adjacent the sprocket ahead of the aperture, the films passing under tension through the fluid chamber prior to passing through the aperture, the fluid chamber containing a source of fluid applied to one or more faces of the films to pull the film perforations against the sprocket teeth on the rotating sprocket on both sides of the sprocket so as to equalize the tension on both sides of the films for engaging the perforations on both sides of the films with the sprocket teeth equally as the sprocket rotates to move the film past the aperture.
Dependencies are inferred from the claim text.