Light deflector and image forming apparatus

摘要

Light deflector includes: polygon mirror made of plastic and having reflecting surfaces; motor rotatable on a rotation axis; and rotor rotatable by the motor, and including base portion intersecting the axis of rotation, and first protruding portion having circular cylindrical shape and protruding from the base portion in a rotation-axis direction. The polygon mirror has inner surface contacting outer peripheral surface of the first protruding portion, and bottom surface facing to the rotor in the rotation-axis direction. The bottom surface has contacting portion contacting the base portion, and the contacting portion overlaps a line segment connecting the rotation axis and any of vertexes of the polygon mirror viewed from the rotation-axis direction. The bottom surface has non-contacting portion spaced apart from the base portion, and the non-contacting portion overlaps a perpendicular dropped from the rotation axis to any of the reflecting surfaces viewed from the rotation-axis direction.

主权项

1. A light deflector comprising:
a polygon mirror made of plastic and having a plurality of reflecting surfaces; a motor configured to rotate on an axis of rotation; and a rotor configured to be rotatable by the motor, and including a base portion intersecting the axis of rotation, and a first protruding portion having a circular cylindrical shape and protruding from the base portion in a direction of the axis of rotation, wherein the polygon mirror has an inner surface contacting an outer peripheral surface of the first protruding portion of the rotor, and a bottom surface facing to the rotor in the direction of the axis of rotation, wherein the bottom surface of the polygon mirror has a contacting portion configured to contact the base portion of the rotor, and the contacting portion overlaps a line segment connecting the axis of rotation and any of vertexes of the polygon mirror viewed from the direction of the axis of rotation, and wherein the bottom surface of the polygon mirror has a non-contacting portion configured to be spaced apart from the base portion of the rotor, and the non-contacting portion overlaps a perpendicular dropped from the axis of rotation to any of the reflecting surfaces viewed from the direction of the axis of rotation.