| 摘要 |
In a flying spot film scanner for scanning a cinematograph film frame by frame during continuous movement of the film and producing a television video signal, apparatus is provided which processes signals representative of the direction of film movement, rate of film movement, position of each film frame in a film gate, times for television fields to begin, and rate of vertical deflection in a raster suitable for scanning a stationary film frame, to produce a composite output signal suitable for effecting the vertical deflection and positioning of a raster intended to scan a frame of a film moving so as to give rise to such signals. The required processing is effected by using an up/down position counter in which the number represents the current position of a reference point in whichever film frame is entering a scanning region defined by the film gate, and a composite signal counter in which the counting is started at the beginning of each television field from the loading in of the current number in the position counter and is effected from this number by clock pulses, some of which are representative of the rate of vertical deflection in a raster suitable for scanning a stationary film frame, and others representative of the rate of movement of the film. The direction of counting of the pulses representing the stationary frame raster rate is predetermined in accordance with the orientation of the film frame pictures relative to the apparatus. The direction of counting of the pulses representing the film rate is determined in dependence upon the direction of movement of the film. The number in the composite counter is converted into an analog signal which is supplied to vertical deflection circuitry determining the vertical deflection of the beam of the cathode ray tube producing the scanning raster.
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