Patent ID: 10866409

Abstract:
A light deflecting device includes a rotary polyhedron and a cover that covers the rotary polyhedron. The cover includes an opening facing a peripheral surface of the rotary polyhedron. Light beam is irradiated to the peripheral surface of the rotary polyhedron through the opening of the cover, and the rotary polyhedron allows the light beam to be deflected and scanned with respect to an object to be irradiated while rotating about an axial center thereof. When an opening angle of the opening centered on the axial center of the rotary polyhedron is θ and n is set as a natural number, θ satisfies the following Equation (1) θ>((360°/the number of surfaces of the rotary polyhedron)×n)×0.83 . . . (1) and Equation (2) θ<((360°/the number of surfaces of the rotary polyhedron)×n)×1.17 . . . (2).