Patent ID: 7126735

Claim:
An optical scanning apparatus comprising: a plurality of light sources; a deflector for deflecting beams emitted from the light sources in a main scanning direction; lenses for imaging the deflected beams on receiving surfaces respectively; and diverting mirrors for directing the beams which passed through the lenses to the receiving surfaces respectively, wherein: the deflector is common to the plurality of light sources; the lenses are located in a right side and in a left side of the deflector before the diverting mirrors, and each of the lenses has a surface which is of a shape symmetrical in a sub-scanning direction; and if the diverting mirrors located in an upper optical path in said left side of the deflector are A in number, if the diverting mirrors located in a lower optical path in said left side of the deflector are B in number, if the diverting mirrors located in a lower optical path in said right side of the deflector are C in number and if the diverting mirrors located in an upper optical path in said right side of the deflector are D in number, the following conditions are satisfied: |A−B|= 2 ×i+ 1 |C−D|= 2 ×j+ 1 |A−D|= 2 ×m+ 1 |B−C|= 2 ×n+ 1 wherein, i, j, m and n are integers not less than 0.