Abstract: An imaging device having a printhead unit which includes a plurality of independently controllable light sources, each light source generating a light beam when activated; a photoconductive surface operable at a plurality of image transfer rates; a scanning device having one or more deflecting surfaces, the scanning device arranged to direct the light beams so as to sweep in at least one scan direction across a surface such that, for each sweep, scan lines written by the light beams are spaced from one another on the photoconductive surface in a process direction that is nominally orthogonal to the scan direction; and a controller configured to selectively activate any number of the light sources for use during a print operation to write image data along scan lines on the photoconductive surface, wherein a rotational velocity of the scanning device is selected and the number of the light sources activated based upon at least one selected operating parameter for the imaging device.

Abstract: Methods are provided for an EP device such as a laser printer or copier, to compensate for variations in scanning rate. At intervals during a scanning process, actual scanning rate is measured and compared to a basal scanning rate of the EP device. Adjustments in the laser light source intensity are then implemented to preserve a predetermined image darkness notwithstanding variations in scanning rate, thereby preserving print quality. To implement the adjustments, a compensation factor is calculated based on a difference between the basal scanning rate of the device and the measured actual scanning rate. The steps of measuring an actual scanning rate, calculating a compensation factor, and adjusting laser operating intensity may be performed during a warming-up function at EP device at start-up, during a print job, or both. An EP device utilizing the method of the present invention is provided also.

Abstract: Methods are provided for an EP device such as a laser printer or copier, to compensate for variations in scanning rate. At intervals during a scanning process, actual scanning rate is measured and compared to a basal scanning rate of the EP device. Adjustments in the laser light source intensity are then implemented to preserve a predetermined image darkness notwithstanding variations in scanning rate, thereby preserving print quality. To implement the adjustments, a compensation factor is calculated based on a difference between the basal scanning rate of the device and the measured actual scanning rate. The steps of measuring an actual scanning rate, calculating a compensation factor, and adjusting laser operating intensity may be performed during a warming-up function at EP device at start-up, during a print job, or both. An EP device utilizing the method of the present invention is provided also.