Patent ID: 8675035

Claim:
An optical scanning unit, comprising: a light source unit including a light source configured to emit a light beam; an optical housing configured to receive and support the light source unit, the light source unit being attached to the optical housing in an optical axis direction of the light source and fittable to the optical housing, the optical housing setting a clearance around peripherals of the light source unit, the optical housing including a projected portion that defines an opening through which the light source unit is supported in the optical housing along the optical axis direction of the light source; a holder engaging the optical housing in the optical axis direction of the light source, the holder including a concave portion that defines an other clearance around the projected portion of the housing, the other clearance being perpendicular to the optical axis direction of the light source; an optical device configured to deflect the light beam and to focus the light beam onto a light receiving member; and a biasing member configured to apply a biasing force to the light source unit in a direction perpendicular to the optical axis direction of the light source at the concave portion of the holder with a presence of the clearance about the optical axis of the light source, wherein the concave portion of the holder is spaced apart from the projected portion of the housing in the direction perpendicular to the optical axis direction of the light source, and the biasing member is configured to apply the biasing force to the holder in the direction perpendicular to the optical axis of the light source at a position of the holder that is opposite the concaved portion of the holder in the direction perpendicular to the optical axis of the light source.