A non-contact laser engraving apparatus for reproducing on a workpiece an image, the image being formed on or in proximate relationship to a specularly reflecting surface of a cyclindrical mirror being scanned laterally by a laser beam with the mirror in a focal plane. The image is formed of a diffusely...http://www.google.com/patents/US4480169?utm_source=gb-gplus-sharePatent US4480169 - Non contact laser engraving apparatus
