Optical scanning apparatus capable of reducing variations in shading and improving light usage

An image forming apparatus comprising:

• a light source generating a laser beam;
• a deflector having a reflective surface arranged relative to the light source to deflect the laser beam via the reflective surface in a light deflection direction;
• a scanning lens arranged relative to the deflector to focus the deflected laser beam at a spot on a scanning surface to thereby perform optical scanning;
• and
• an aperture located between the light source and the deflector, the aperture having a substantially square shape;
• wherein
• the light source, the deflector and the scanning lens are located along an optical axis and the light source is tilted relative to the optical axis by an angle of about 45° and generates the laser beam such that the laser beam which is impinged on the reflective surface is light polarized in a direction between a direction that is parallel to the light deflection direction and a direction that is perpendicular to the light deflection direction.

A method of manufacturing an optical scanning apparatus comprising the steps of:

• providing a light source generating a laser beam;
• arranging a deflector having a reflective surface to deflect the laser beam via the reflective surface in a light deflection direction;
• arranging a scanning lens to focus the deflected laser beam at a spot on a scanning surface to thereby perform optical scanning;
• and
• arranging an aperture between the light source and the deflector, the aperture having a substantially square shape;
• wherein
• the light source, the deflector and the scanning lens are located along an optical axis and the light source is tilted relative to the optical axis by an angle of about 45° and generates the laser beam such that the laser beam which is impinged on the reflective surface is light polarized in a direction between a direction that is parallel to the light deflection direction and a direction that is perpendicular to the light deflection direction.