Laser imaging system for imaging printed circuit artwork on an output medium such as a photosensitive film, a glass plate or a printed circuit board. The laser beam scans the output medium and is modulated in accordance with the image to be formed. A correction signal is applied to the modulator to maintain...http://www.google.com.au/patents/US4422083?utm_source=gb-gplus-sharePatent US4422083 - System and method for producing artwork for printed circuit boards
