Patent ID: 7639413

Claim:
An apparatus for use in optical scanning, 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 comprising: (a) a reflective mirror having the light-reflective surface; (b) an integral spring extending from the reflective mirror and being excited to generate at least a torsional vibration; and (c) a stationary member cooperating with the reflective mirror to support the integral spring, the integral spring having both ends coupled to the stationary member, wherein the integral spring includes: a first spring portion, coupled at its one end to the reflective mirror, and excited to generate a torsional vibration; and a plurality of second spring portions coextending from a remaining end of the first spring portion in a bifurcation fashion, coupled to the stationary member, and excited to generate a bending vibration and a torsional vibration, and wherein: 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 disturbing vibration being in the form of a vibration of the integral spring other than the torsional vibration thereof and being a lateral vibration in which the reflective mirror is vibrated in a direction parallel to the light-reflective surface; the shape-defining parameter is defined as a percentage of lengthwise dimensions of the plurality of second spring portions with respect to a lengthwise dimension of the integral spring; and 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.