OPTICAL DIAPHRAGM DEVICE

摘要

PROBLEM TO BE SOLVED: To easily control the diameter of a light beam projected from a light source. SOLUTION: A light beam B1 is projected from a laser diode 11 based on an output signal from a laser diode driving circuit 12. The beam B1 is led into a Digital micromirror device (DMD)(R) 20 to be a light reflecting means by a collimator lens 30 as a parallel beam. Respective micromirrors formed like a matrix on the DMD 20 are ON/OFF controlled and properly tilted to a 1st or 2nd tilting direction to control the diameter of a light beam B2 and switch the resolution of an electrostatic latent image formed on a photoreceptor drum D.