Light scanning apparatus and image forming apparatus including the same

An apparatus comprising:

• a deflecting unit configured to deflect a light flux from a light source to scan a scanned surface in a main scanning direction;
• and
• an imaging optical system configured to guide the deflected light flux to the scanned surface,
• wherein a width of the light flux is larger than the width of a deflecting surface of the deflecting unit in a main scanning cross section when the light flux is incident on the deflecting surface,
• wherein a scanning speed of the light flux on the scanned surface is different between an on-axis image height and an outermost off-axis image height, and
• wherein a first region between the on-axis image height and the outermost off-axis image height at one side is longer than a second region between the on-axis image height and the outermost off-axis image height at the other side with respect to an optical axis of the imaging optical system on the scanned surface.