Beam scan type laser pattern marking method and apparatus and mask used in the apparatus

摘要

The energy distribution in the cross section of the laser beam is equalized by emitting a laser beam from a laser oscillator made of an acoustooptic Q switch element by a continuous wave Q switch pulse and passing the mask having a mask pattern. The laser beam passing through the mask is reflected by a pair of reflective mirrors provided on a pair of galvanometers. This reflected laser beam is focused on the workpiece through the objective lens. The desired character or mark is marked on the workpiece by scanning with a laser beam focused on the workpiece by driving a pair of galvanometers.