Patent ID: 6295163
Filing Date: 2001-09-25
Classification: G02B

Abstract:
A scanning optical apparatus comprising:a light source;a conversion optical element for converting a light beam emitted by said light source into a substantially collimated light beam;a deflection element for deflecting the converted substantially collimated light beam; anda scanning optical element for forming an image of the light beam deflected by said deflection element on a surface to be scanned,wherein said scanning optical element comprises at least one refractive optical element and at least one diffractive optical element having a diffraction grating, said diffraction grating being formed on a substrate surface and having a tilt portion for generating power and a wall portion connecting one end portion of said tilt portion to the substrate, and said wall portion being tilted with respect to a normal to the substrate surface, and a tilt angle .theta.e of said wall portion with respect to the normal to the substrate surface continuously changes to increase as a distance from an optical axis of said diffractive optical element becomes large.