Patent ID: 7986334

Claim:
An image forming apparatus comprising: a plurality of image carriers each of which configured to bear an image on a surface thereof; and an optical writing device configured to optically scan the surface of each of the image carriers, the optical writing device including: a plurality of light sources configured to emit light beams whose wavelengths are different from each other; a deflector configured to deflect the light beams that are emitted from the light sources and synthesized on an identical axis in a sub-scanning direction; at least one set of optical devices including a first imaging device configured to narrow the light beams in a main scanning direction, a second imaging device configured to narrow the light beams in the sub-scanning direction, a first beam separator located between the first imaging device and the second imaging device, configured to receive the light beams deflected by the deflector and transmit or reflect the light beams according to travel directions of the light beams, and a second beam separator located between the first imaging device and the second imaging device, configured to transmit or reflect the light beams transmitted through the first beam separator according to wavelengths of the light beams and cause the light beam reflected thereon to be reflected on the first beam separator, the optical writing device configured to scan the surface of one of the image carriers with the light beam transmitted through the second beam separator and the surface of another image carrier with the light beam reflected on the first beam separator after being reflected by the second beam separator.