Film constraint and film writing system
AssigneeEastman Kodak Company
InventorRobert C. Bryant
Life of this patent
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Abstract
A rigid cylinder is rotated about its axis of symmetry at a relatively high rate of speed by means of a motor. Around a portion of the circumference of the rotating cylinder is wrapped a flexible imaging medium such as photographic film, to which is applied longitudinal tension through means of a film transport. The film conforms to the curvature of the drum, but is held a small distance above the surface of the cylinder in equilibrium between the aerodynamic forces created by the rotating cylinder and the applied tension of the film transport, thus effecting a compliant surface air bearing. A scanning beam is used to write on the film in the line direction. Longitudinal movement of the film is used to affect scanning in the page direction.
Claims9
A film gate for frictionlessly constraining film said gate comprising:
- a film transport for transporting said film longitudinally in either direction while maintaining a predetermined tension in said film;
- means for controlling said film transport to accurately position the desired portion of the film in the gate;
- a cylinder aligned with its major axis perpendicular to the longitudinal movement of said film;
- drive means for rotating said cylinder about its axis;
- inlet and outlet constraint means located adjacent said cylinder so as to define a path for said film around a portion of the periphery of said cylinder where it is held a small distance above the surface of the cylinder by a balance of aerodynamic forces developed by the rotating cylinder and the applied tension of the film transport;
- and
- means for writing a line of information across the film in said film gate.
Dependencies are inferred from the claim text.