Abstract: An improved method is provided for compensating for pixel site defects of a spatial light modulator (30) in an imaging apparatus (10). An image is formed at a first position and directed to a surface (36). Then, an actuator (40) shifts the spatial light modulator (30) over a shift distance to a second position, which is some integer multiple n of the distance between pixels (72) on the spatial light modulator (30). A second image is formed on the spatial light modulator (30), shifted by the shift distance, and directed to the surface (36). Optionally, dithering is provided with an additional shift of an increment of the distance between pixels (72).

Abstract: An improved method is provided for compensating for pixel site defects of a spatial light modulator (30) in an imaging apparatus (10). An image is formed at a first position and directed to a surface (36). Then, an actuator (40) shifts the spatial light modulator (30) over a shift distance to a second position, which is some integer multiple n of the distance between pixels (72) on the spatial light modulator (30). A second image is formed on the spatial light modulator (30), shifted by the shift distance, and directed to the surface (36). Optionally, dithering is provided with an additional shift of an increment of the distance between pixels (72).

Abstract: A method for mapping a limited number of input data values to a larger number of output exposure values for an electro-optical exposure device in a printing system (10) for photosensitive medium (30) in which, based on a computed contrast ratio for the photosensitive medium (30), the electro-optical exposure device is profiled and its output exposure energy curve adjusted to obtain the desired exposure energy over the range of input values.

Abstract: A method for improving exposure resolution that includes several steps. A high gray scale resolution image is analyzed and a determination is made of a media plane (331) exposure gray scale resolution requirement. Exposure time and an exposure intensity is determined for each of the low gray scale resolution intermediate images. A number of low gray scale resolution intermediate images (332) are required to provide the media plane exposure resolution; and an exposure time and exposure intensity (333) for each of the low resolution intermediate images is determined. An image content for each of the low gray scale resolution intermediate images is determined (334) and each of the low resolution intermediate images is printed (335) at the exposure time and the exposure intensity.

Abstract: Compensation for space charge build-up in an electro-optic modulator device is realized by recurrently recalibrating the device. During each recalibration interval, light transmitted through the device is intercepted and converted to an electric signal which is compared to a test signal of a magnitude corresponding to light of an intensity that would be transmitted through the device in the absence of space charge. The difference between the respective magnitudes of the test signal and the electric signal serves as a bias to supplement the normal modulating drive signal until the time of next recalibration. Recurrently, but at a rate lower than the recalibration rate, the device is short circuited, while flooded with light, to eliminate space charge build-up.