Abstract: A deformable mirror device having a two-dimensional array of mirror elements is driven in such a way to reduce the data rate and remove the need for buffer stores. The mirror elements are loaded row-by-row in response to an n bit video signal in 2n loading operations. Only n rows are loaded in each loading operation, the other rows remaining in their previous conditions, and the loading continues sequentially down the array. The timing of the loading is such that the duration from loading a given row with a first data bit to loading the same row with the next data bit is proportional to the significance of the first data bit.

Abstract: A processing system for a spatial light modulator in the form of an array of defomable mirror devices receives a gamma-corrected, video input signal. A de-gamma processor removes all or part of the gamma-correction of the video input signal to match the data to the form of the spatial light modulator.

Abstract: A spatial light modulator in the form of a deformable mirror device (110) receives from a frame store (116) data which has been formatted by a data formatter (114) subsequent to gamma correction in a ROM look-up table (112). The DMD (110) displays different light levels by being ON for selected periods of a series of durations 4, 8, 16 . . . 1024 varying in proportion to a basic period multiplied by powers of two. The shortest duration 4 for which the DMD can be turned on is a multiple of the basic period, and the series includes additional durations 5, 6 and 7 in the series between the shortest displayable duration 4 and the next power of two 8. Durations 1, 2 and 3 of less than the shortest displayable duration can be displayed by adjusting the turn-on time of a proportion of the adjacent mirrors. The longest duration for which the mirror can be turned on can be employed twice.

Abstract: A processing system for a spatial light modulator in the form of an array of deformable mirror devices receives a gamma-corrected, color component, video input signal. The input signal is converted to pixel data which is then converted to RGB data. A de-gamma processor removes all or part of the gamma-correction of the pixel data to match the data to the form of the spatial light modulator.

Abstract: A spatial light modulator in the form of a deformable mirror device receives from a frame store data which has been formatted by a data formatter subsequent to gamma correction in a ROM look-up table. The DMD displays different light levels by being ON for selected periods of a series of durations 4, 8, 16, - - - , 1024 varying in proportion to a basic period multiplied by powers of two. The shortest duration 4 for which the DMD can be turned on is a multiple of the basic period, and the series includes additional durations 5, 6, and 7 in the series between the shortest displayable duration 4 and the next power of two 8. Durations 1, 2, and 3 of less than the shortest displayable duration can be displayed by adjusting the turn-on time of a proportion of the adjacent mirrors. The longest duration for which the mirror can be turned on can be employed twice.

Abstract: A deformable mirror device having a two-dimensional array of mirror elements is driven in such a way to reduce the data rate and remove the need for buffer stores. The mirror elements are loaded row-by-row in response to an n bit video signal in 2.sup.n loading operations. Only n rows are loaded in each loading operation, the other rows remaining in their previous conditions, and the loading continues sequentially down the array. The timing of the loading is such that the duration from loading a given row with a first data bit to loading the same row with the next data bit is proportional to the significance of the first data bit.

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.

Abstract: This invention concerns a circuit for detecting vertical mis-registration in a flying spot scanner of the kind in which each film frame is scanned by at least two interlaced fields.For proper vertical registration each line of each field should fall midway between two adjacent lines of the other field. This means that, on average, the mean video signal value of each line of one field should equal the mean video signal value of the two adjacent lines of the other field.Our invention detects whether this is so by forming the difference between the means video signal values of each line of one field with that of the two adjacent lines of the other field, and summing over a number of lines.

Abstract: Errors in the raster of a flying spot scanner are measured by placing a semi-reflecting surface in the path of the light to the object being scanned to form a secondary raster image in a position where such measurements can be made without interfering with the primary scanning operation. Preferably a feed-back circuit is used to control the cathode ray tube in dependence upon the measurement.