CONTINUOUS TONE RECORDING SYSTEM USING LASER BEAM

摘要

557-2926 A continuous tone image recording system includes a solid state laser diode for generating an analog signal-controlled, intensity-modulated beam of light. Also included is a feedback circuit responsive to the instantaneous intensity of the light beam for continuously providing a feedback control signal coupled to the laser diode for adjusting the laser diode to stabilize its light output. This allows virtually instantaneous changes in output intensity in response to an input signal while maintaining the output constant regardless of changes in the characteristics of the laser diode. The system also includes a lens, mirror, or prism for collimating, focusing, and controlling the path of the beam of light. Also included in the system is a mirror, galvanometer or deflector for scanning the light beam across the width of an image plane at which a photosensitive recording medium having a sensitivity and exposure range matched to the intensity-modula-ted light beam may be positioned to provide scan lines on the recording medium. The scanned lines are positioned consecutively and accurately along the length of the image plane. The combination of the recited elements enables the formation at the image plane of a continuous tone image, the elements being capable of creating at least 64 gray levels when imaged onto a transparent medium or at least 32 gray levels when imaged onto an opaque medium.