Method and device for correcting vertical framing errors

A method of correcting vertical framing errors in the projection of an intermittently transported perforated motion picture film in projection apparatus that includes a film transport sprocket engaging film perforations, said sprocket being driven by an electric motor whose rotor is connected with an angle indicator deice which delivers position signals corresponding the angular position of the rotor to a regulating device controlling said electric motor, comprising the steps of

• storing framing errors that occur during projection in error tables,
• measuring frame positions,
• comparing recorded measured values with the values stored in said error tables,
• preparing an error table optimally representing said measured values,
• and selecting a correction table corresponding to this error table whose correction values are delivered to regulating device.

A method for correcting vertical framing errors in the projection of an intermittently transported perforated motion picture film in projection apparatus that includes a film transport sprocket engaging film perforations, said sprocket being driven by an electric motor whose rotor is connected with an angle indicator device which delivers position signals that correspond to the angular position of said rotor to a regulating device for controlling said electric motor,

• comprising the steps of
• continuously measuring frame positions by detecting a film-integral mark,
• continuously correcting a stored error table with said on-going measured values,
• summing deviations of actual value positions of the frames from a set value indication that shows the correct frame positions over a plurality of frames,
• dividing said summed differential values by the number of measured values, and
• supplying to said regulating device the resulting quotient value as an average for correcting said regulating device.

A method of correcting vertical framing errors in the projection of an intermittently transported perforated motion picture film in projection apparatus that includes a film transport sprocket engaging film perforations, said sprocket being driven by an electric motor whose rotor is connected with an angle indicator device which delivers position signals corresponding to the angular position of the rotor to a regulating device controlling the electric motor, comprising the steps of

• measuring the frame positions with a measuring film over a plurality of frames,
• storing corresponding frame position indications,
• storing framing errors that occur during projection in error tables, measuring frame positions continuously,
• comparing recorded measured values with values stored in said error tables,
• preparing an error table which optimally represents the measured values,
• selecting a correction table corresponding to said error table whose correction values are delivered to said regulating device, and changing the position of said angle indicator device relative to said film transport sprocket by said correction value.

A method of correcting vertical framing errors in the projection of an intermittently transported perforated motion picture film in projection apparatus that includes a film transport sprocket engaging film perforations, said sprocket being driven by an electric motor whose rotor is connected with an angle indicator device which delivers position signals corresponding to the angular positions of said rotor to a regulating device controlling said electric motor,

• comprising the steps of
• measuring frame positions with a measuring film over a plurality of frames,
• storing the corresponding frame positions,
• continuously measuring said frame positions by detecting a film-integral mark,
• continuously correcting a stored error table using said on-going measured values,
• summing the deviations of actual value positions of the frame from a set value corresponding to the correct frame stop position over a plurality of frames, dividing the summed differential values by the number of measured values for use as an average for correcting, supplying said average value to said regulating device, and changing the position of the angle indicator device relative to the film transport sprocket by a correction value.