Patent ID: 7133175

Claim:
A light bean deflecting device comprising: (a) a rotor portion fixed on an outer circumference of a bearing; (b) a polygon mirror stuck and fixed on a supporting section of the rotor portion; and (c) an elastic material pressing against a first surface of the polygon mirror to hold the polygon mirror on the supporting section, wherein the rotor portion has a cylinder portion fixed on the outer circumference of the bearing, the supporting section and a disc-shaped flange portion being provided on an end portion of the cylinder portion, and wherein a clearance is provided between an inner circumference of the cylinder portion on an end portion side where the flange portion is provided and an outer circumference of the bearing, and wherein a bottom surface position of the supporting section is located further from the first surface of the polygon mirror than a lowermost surface position of the clearance in an axial direction of the bearing.