| 摘要 |
The dynamic range of a continuous tone laser printer is extended by directly modulating a diode laser (12) while simultaneously modulating the optical output of the diode laser with an acousto-optic modulator (14). The digital image value is input to two look-up tables (LUTs) (32) that convert the image value to two digital words; one to set the power level of the diode laser (12), and the other to set the diffraction efficiency of the acousto-optic modulator (AOM) (14). The first look-up table is constructed from the performance characteristics of the diode laser (12), and the second look-up table is constructed from the performance characteristics of the AOM (14). The look-up table digital outputs are applied to respective digital to analog converters (34, 38) whose analog outputs respectively drive a voltage to current driver (36) for the diode laser (12) and a radio frequency driver (40) for the AOM (14). The resulting power of the writing laser beam is a linear function of the input image value. |
