A calligraphic writing system of the type including an x-y plotter, a writing pen and a digital computer that controls the movement of the pen relative to the writing bed of the plotter. The system self-aligns the writing pen and items on the bed being written, and permits a number of items to be correctly...http://www.google.com.hk/patents/US4794403?utm_source=gb-gplus-share專利 US4794403 - Writing system
