Patent ID: 6943927

Claim:
An optical scanning apparatus comprising: a light source; deflecting means; entrance optical means for guiding light emitted from the light source to the deflecting means; and scanning optical means for forming an image of the light reflectively deflected by the deflecting means, on a surface to be scanned; wherein said scanning optical means asymmetrically changes curvatures in a sagittal direction at respective positions in a meridional direction; wherein the curvatures in the sagittal direction at respective positions in the meridional direction facing in one off-axis direction across an optical axis comprise a plurality of sagittal deformation surfaces of which magnitude relation is larger than that in curvatures in the sagittal direction at respective positions in the meridional direction facing in another off-axis direction across the optical axis; and wherein the sagittal deformation surfaces comprise two or more surfaces in which the curvatures in the sagittal direction at the respective positions in the meridional direction increase or decrease on a same side.