Polygon mirror scanner device with tubular magnet adhered to the inside of the tubular mirror with a depression on the inner face, opposite the mirror face, with a gap, absent adhesive, formed between the magnet and inner face

Abstract

Disclosed is a polygon mirror scanner device, used as a rotor, having a plurality of mirror faces on the outer peripheral face of a mirror member having a substantially tubular shape, with a tubular magnet adhered to the lower inner peripheral face of the mirror member. A depression is uniformly formed in the circumferential direction on the inner peripheral face, at a position opposite the mirror faces, such that a gap forms between the magnet and the inner peripheral face when the magnet is at a predetermined positioned. An adhesive agent is provided at the upper end and lower end of the magnet, but not in the gap. When the mirror faces are two-tiered, the upper end of the magnet is located at substantially an intermediate position in the height direction of the two-tier mirror faces.