Laser beam tertiary positioner apparatus and method

Abstract

A tertiary positioner system (80) of this invention employs X- and Y-axis translation stages (86, 88), galvanometer-driven mirrors (64, 66), and a fast steering mirror (“FSM”) (120) to direct a laser beam (90) to target locations (121) on a workpiece (92). A positioning signal is received by a low-pass filter (103) that produces filtered position data for driving the X- and Y-axis translation stages. The actual positions of the X- and Y-axis translation stages are subtracted from the unfiltered positioning data to produce an X-Y position error signal for driving the galvanometer-driven X- and Y-axis mirrors. The actual mirror positions are subtracted from the actual positions of the X- and Y-axis translation stages to generate a positional error signal representing the difference between the commanded and actual positions of the laser beam. The positional error signal drives the FSM to rapidly correct any positional errors.

Dependencies are inferred from the claim text.