Patent ID: 7385745

Claim:
A two-dimensional scanning apparatus comprising: deflecting means for deflecting a beam emitted from light source means in a first scanning direction and a second scanning direction orthogonal to said first scanning direction; and a scanning optical system including, in order from the deflecting means, a first reflecting surface and a second reflecting surface, the first and second reflecting surfaces having rotationally asymmetrical shapes, and directing the deflected beam deflected by said deflecting means onto a surface to be scanned, said first and second reflecting surfaces being disposed so as to fold an optical path of said deflected beam in said first scanning direction; wherein a principal ray of a beam incident on the center of an angle of view of said surface to be scanned is inclined incident on said surface to be scanned in at least the first scanning direction of said first and second scanning directions, and wherein when the principal ray is set as a reference axis, said first scanning direction is in parallel with a plane containing the reference axis, wherein the first reflecting surface includes a first concave surface of which shape in a section in parallel with said second scanning direction is concave, and a first convex surface of which shape in a section in parallel with said second scanning direction is convex, wherein the second reflecting surface includes a second concave surface of which shape in a section in parallel with said second scanning direction is concave, and a second convex surface of which shape in a section in parallel with said second scanning direction is convex, wherein the beam emitted from the first concave surface is incident into said surface to be scanned through the second convex surface, and wherein the beam emitted from the first convex surface is incident into said surface to be scanned through the second concave surface.