Film scanner employing optical splice technique for frame-rate conversion

Claim 1

A film scanner for producing television signals from motion picture film, comprising: a stationary film gate, said film gate defining an opening having a top and bottom edge, the opening between the top and bottom edges of said film gate being larger than one film frame height; means for moving the film continuously past the opening at a controlled rate; means for projecting an image of the film in said gate; a solid-state line sensing array for scanning the image of the film, line by line, in a direction generally perpendicular to the length of the film at a standard television line rate to produce a television signal; multifacet mirror means having a plurality of reflecting facets disposed about a central axis, said mirror means being journalled for rotation about said axis and being disposed with respect to said projection means for reflecting the image of the film onto said array such that reflections from adjacent facets will be displaced by substantially one film frame height, whereby the reflected images of said film gate from adjacent facets overlap; means for rotating said mirror means about said axis at a controlled rate to thereby cause an image reflected by one of said facets to sweep across said array, in effect causing said array to repeatedly vertically scan said film gate from one of said edges to the other at a controlled rate; means for fading-in the projected image reflected by a facet at the beginning of the sweep across the line sensor and for fading-out the projected image reflected by a facet at the end of a sweep across the line sensor such that the percentage of light reaching the sensor remain substantially constant; and control means for controlling said film moving means at X frames per second and for controlling said rotating means at Y facets per second such that X+Y is equal to a standard television field rate, and wherein X is a non-integral submultiple of the television field rate, whereby exact frame-rate conversion is achieved by forming a television field from portions of two adjacent film frames whenever the vertical scan reaches an edge of the film gate before the scan of a film frame has been completed.