Automatic scanning device and its control for opto-mechanical processing applications

An automatic scanning device for the opto-mechanical processing of a substrate covered with photo-sensitive material, said substrate comprising a drum rotating about its central axis, said processing being accomplished by means of optical components supported by a carriage moving along a rectilinear guide, comprising:

• a light source for generating a light beam;
• optical means mounted on said carriage for guiding the beam generated by the source onto said substrate;
• a control computer;
• a position measuring device coupled to determine the position of the carriage and to provide said position information to said control computer, said position measuring device comprising an optical grating and a detector transmitting its data to said control computer;
• a magnet coupled to said carriage;
• and
• a linear motor comprising a winding, composed of a number of isolated conductors, attached to said rectilinear guide orthogonally to the longitudinal axis of said guide, and connected to said control computer through a controllable current source, and a solid-state commutator coupled to magnetically propel the carriage in a controlled fashion in accordance with current supplied to the winding from said controllable current source based on instructions from said control computer, said linear motor winding further comprising a two-layer printed circuit board, bearing on both sides a repetitive pattern of S-shaped conductors, attached to said rectilinear guide through a thin layer of isolating material.

A method for controlling and steering the scanning for the opto-mechanical processing of a substrate covered with a photo-sensitive material utilizing an automatic scanning device having optical components supported by a carriage moving along a rectilinear guide, comprising:

• generating a light beam;
• guiding the light beam onto said substrate by optical means mounted on said carriage;
• determining the position of said carriage and providing this positional information to a control means;
• controlling the movement of the carriage utilizing a linear motor coupled to the control means through a controllable current source, said linear motor comprising a winding, composed of a number of isolated conductors, attached to said rectilinear guide orthogonally to the longitudinal axis of said guide, and connected to said control means through a controllable current source, and a solid-state commutator coupled to magnetically propel the carriage by magnetically coupling to a magnet mounted on said carriage in a controlled fashion in accordance with current supplied to the winding from said controllable current source based on instructions from said control means.