By Alteration Of Film Path Length Patents (Class 352/161)
  • Patent number: 5082357
    Abstract: Method for correcting vertical framing errors during the projection of an intermittently transported perforated motion picture film by means of a film transport sprocket engaging the film perforations, said sprocket being driven by an electric motor whose rotor is connected with an angle indicator device which delivers to a regulating device controlling the electric motor, position signals corresponding to the angular position of the rotor. To correct device-specific vertical framing errors, the frame positions are measured with a geometrically precise measuring film over a plurality of frames, the individual frame positions are stored, and the position of the angle indicator disk is changed by a correction value relative to the film transport sprocket.
    Type: Grant
    Filed: October 11, 1990
    Date of Patent: January 21, 1992
    Inventors: Josef Haas, Ernst Tschida