Laser control apparatus for controlling a laser beam with respect to a working area to trace a desired pattern on a working area comprises an input device for inputting the desired pattern; a memory for storing a line pattern; a display for displaying the pattern; and a control system for controlling...http://www.google.co.uk/patents/US4587396?utm_source=gb-gplus-sharePatent US4587396 - Control apparatus particularly useful for controlling a laser
