Patent ID: 6894817

Claim:
An optical deflection device comprising: (a) a rotor unit including a magnet, a rotary polygon mirror having a plurality of mirror surfaces on a side surface portion thereof, and a holding member for holding the polygon mirror and the magnet; (b) an air dynamic pressure bearing having a rotary bearing member to be fixed to the rotor unit through the holding member and a fixed bearing member for rotatably supporting the rotary bearing member by air dynamic pressure; and (c) a stator unit which supports the fixed bearing member, and which has a winding coil arranged opposite to the magnet for driving the rotor unit, wherein before a process of assembling and fixing the rotary bearing member to the holding member, an adhesive layer is formed between an outer peripheral surface of the rotary bearing member and an inner peripheral surface of the holding member, and wherein an inner diameter of the holding member before the assembling process is greater than or equal to an outer diameter of the rotary bearing member before the assembling process.