Resonant optical scanner using vibrating body with optimized resonant frequency characteristics and image forming apparatus having the same

摘要

An apparatus for use in optical scanning is disclosed which vibrates at least a part of a vibrating body having a light-reflective surface, to thereby allow light, upon entry, to be reflected from the light-reflective surface in varying directions. The vibrating body includes: (a) a reflective mirror having the light-reflective surface; and (b) an integral spring extending from the reflective mirror and being excited to generate at least a torsional vibration. The vibrating body has vibrational characteristics in which whether or not a resonant frequency of the torsional vibration and a resonant frequency of a disturbing vibration are equal to each other depends upon a shape-defining parameter for defining a shape of the integral spring extending lengthwise. The shape-defining parameter is pre-set to fall within a range allowing the resonant frequency of the torsional vibration and the resonant frequency of the disturbing vibration to be different from each other.