Laser printer having athermalized optical heads

摘要

A laser printer is disclosed which is adapted to be used for color imaging. The printer comprises three diode lasers, each of which emits at a different wavelength. Each laser beam is passed through an apodizing mask to trim the final spot size. The beams from the three lasers are combined by the use of dichroic mirrors to form one combined beam. The combined beam is shaped by two spherical mirrors and is scanned onto a receiving medium by a polygon. The receiving medium is sensitive to the infrared, and the diode lasers are selected to obtain the widest possible spectral separation in the light beams from the lasers.