A laser recorder for recording images on a substrate in response to a video signal having a frequency which defines a pixel time (during which a single pixel is imaged) includes a duty cycle modulating digital to analog (D/A) converter which outputs a variable duty cycle high frequency signal, based...http://www.google.com/patents/US5216443?utm_source=gb-gplus-sharePatent US5216443 - Programmable intensity smart laser system capable of being fabricated on a semiconductive substrate
