in amplitudenmodulations and pulsamplituden - modulation method for diode laser

摘要

A laser imaging apparatus includes a laser diode (16) which is controlled to produce a laser beam the power of which varies linearly as a function of a digital image input signal (12). The laser beam is deflected by scanning optics to expose photosensitive media such as film. When the digital image input signal (12) is in a first range of values to operate the laser diode (16) in its linear region, the laser diode (16) is controlled (24),(28) to operate in an amplitude modulation mode. When the digital image input signal (12) is in a second, lower, range of values which would operate the laser diode (16) in its non-linear operating region, the laser diode (16) is controlled (26),(30) to operate in the linear region but in a pulse amplitude modulation mode. IMAGE