| 摘要 |
A display terminal is provided which holds a roll of film, and can project the image of any film frame onto a console screen. The need for a platen to precisely locate a frame on the optical imaging plane, is avoided by keeping the film in tension. The tension is maintained while the film is stationary, by utilizing a pair of reel-driving motors that each provide a torque that varies with the diameter of the film roll on the corresponding reel. The film region being projected, can be held in a slight curve to more reliably hold all areas of the projected film region near a predetermined film plane. A film identification track and clock track can extend along one edge of the film to identify every frame and accurately center the frame at the imaging, or projection, station. The film can be rapidly moved to bring a desired frame to approximately the imaging station, with slight overshoot, and the film then can be inched back to center the frame.
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