Abstract: In a laser drawing apparatus, a pattern is drawn on a workpiece by scanning the workpiece with at least one laser beam. The laser beam is modulated on the basis of raster-graphic data, in accordance with a series of clock pulses. A calculator calulates clock-pulse-phase-shift location data, indicative of where a phase of the clock pulses should be shifted, with a unit of less than 2.PI.. The calculation is made on the basis of pixel-dot-pitch discrepancy data measured along a scanning line defined by the scanning laser beam. A clock-pulse-outputting controller controls outputting the clock pulses so that the phase of the clock pulses is shifted, with the unit of less than 2.PI.. The shift occurs whenever the laser beam reaches each of the clock-pulse-phase-shift locations, represented by the clock-pulse-phase shift location data, during scanning of the workpiece with the laser beam. Consequently, a pixel-dot-pitch discrepance in the scanning line can be corrected with a unit of less than a one-pixel-dot size.

Abstract: A laser drawing apparatus is used to draw a pattern on a surface of a workpiece by scanning the workpiece surface with at least one laser beam and by modulating the laser beam on the basis of raster-graphic data in accordance with a series of clock pulses. In the apparatus, a detector detects a dimensional variation of the workpiece in a scanning direction of the laser beam with respect to a corresponding standard dimension of an ideal workpiece. A calculator calculates a degree of variation the dimension of the workpiece and the corresponding standard dimension of the ideal workpiece. A regulator serves to cyclically shift a phase of the clock pulses by a unit of less than 2.pi., whereby the pattern to be drawn on the workpiece is dimensionally varied, in accordance with the degree of the dimensional variation of the workpiece.

Abstract: Disclosed is a raster data drawing apparatus, in which a reference clock pulse signal having a predetermined period is first generated, and then a plurality of delayed clock signals are generated. Phases of the plurality of delayed clock signals are shifted by a period of time which is shorter than the predetermined period. An image is formed in a main scanning direction synchronously with one of the plurality of delayed clock signals so that the starting point of the image in the main scanning direction is adjusted.