Optical scanner and image forming apparatus including the same

An optical scanner comprising:

• a light source;
• a deflector deflecting a light beam emitted from the light source;
• an optical element that includes:
• a folding mirror reflecting the light beam deflected by the deflector;
• and an imaging lens imaging the light beam on a photoreceptor drum, and that is arranged in an optical path of the light beam;
• a fixing structure having:
• a first support wall facing a surface of the optical element in a thickness direction thereof;
• a second support wall contacting one end face in a width direction of the optical element perpendicular to the thickness direction;
• and a biasing member biasing the optical element toward the first support wall, and holding the optical element between the biasing member and the first support wall to fix the optical element in the thickness direction and in the width direction;
• and
• a housing that houses the light source, the deflector, the optical element and the fixing structure, wherein
• the first support wall has a support projection having:
• a tip part protruding toward the surface along the thickness direction and abutting on the surface;
• and an inclined surface extending from the tip part to an opposite side of the second support wall,
• a first angle between a first straight line extending in a direction perpendicular to a bottom surface of the housing and another surface of the optical element, opposite to the surface in the thickness direction, is smaller than a second angle between the first straight line and the inclined surface,
• the second angle is smaller than 90 degrees, and
• the tip part is formed as a plane parallel to the surface.