Patent ID: 6731320
Filing Date: 2004-05-04
Classification: G03F

Abstract:
A scanning system comprising:a source of multiple beams; scan optics that sweeps the beams along a scanning direction of scan lines in an image plane, wherein at least one of the beams moves along an associated scan line with a non-uniform velocity; a modulator positioned to separately control intensities of the multiple beams, wherein each scan line is divided into a series of uniform size pixels, and the modulator controls an intensity for each pixel; and a timing generator coupled to provide a first signal to the modulator to indicate boundaries of the pixels in a scan line, the timing generator comprising: a source of pixel period values; a select circuit coupled to select for each pixel one of the pixel period values; and a counter coupled to the select circuit, wherein for each pixel, the counter loads a first value from the pixel period value selected for the pixel, counts for a period of time indicated by the first value, and asserts a second signal marking an end of the period, the first signal being derived from the second signal.