Film scanner with compensation for film shrinkage
AssigneeThe Rank Organisation Limited
InventorsJohn David Millward, John Wright
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Abstract
The invention is concerned with a means of compensating for film shrinkage in a continuous film motion telecine apparatus. A measure of the film shrinkage is obtained by deriving a signal representing the angular speed of a roller in non-slipping contact with the film, the film being driven at a constant frame rate by, for example, a smooth capstan servo-controlled to maintain the constant frame rate. The roller whose angular speed is measured may be the drive capstan itself or a separate roller. The signal so derived is dependent on the film shrinkage and thus is used to automatically control a registration adjusting means to compensate for such shrinkage.
Claims7
In a continuous film motion telecine apparatus, means for deriving a signal representing the angular speed of a roller in non-slipping contact with the film when the film is being driven at a constant frame rate, the value of such signal being dependent upon film shrinkage, and means using said signal to automatically control a registration adjusting means to compensate for such shrinkage.
A telecine apparatus according to claim 23, further comprising means for comparing said signal with a reference value corresponding to unshrunk film to provide a correction signal for controlling the adjustment.
Dependencies are inferred from the claim text.