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Laser drawing apparatus

  • US 6,100,915 A
  • Filed: 08/27/1997
  • Issued: 08/08/2000
  • Est. Priority Date: 08/28/1996
  • Status: Expired due to Fees
First Claim
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1. A laser drawing apparatus for drawing a pattern on a workpiece by scanning the workpiece 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, said apparatus comprising:

  • a calculator for calculating respective clock-pulse-phase-shift location data, to which a phase of said clock pulses should be shifted, with a unit of less than 2π

    , on the basis of pixel-dot-pitch discrepancy data previously measured along equally-divided sections of a scanning line defined by the scanning laser beam; and

    a clock-pulse-outputting controller for controlling outputting of said clock pulses so that the phase of said clock pulses is shifted, with the unit of less than 2π

    , whenever said laser beam reaches each clock-pulse-phase-shift location, represented by said clock-pulse-phase-shift location data, during the scanning of said workpiece with said laser beam, whereby a pixel-dot-pitch discrepancy in each of said equally-divided sections of said scanning line can be corrected with a unit of less than a one-pixel-dot size.

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