Patent ID: 8134584

Claim:
An image forming apparatus, comprising: one or more light sources configured to emit at least a first light beam and a second light beam; a beam deflector that includes a double mirror portion having a first mirror and a second mirror that are not coplanar with respect to each other, the double mirror portion being configured to pivot about a pivotal axis that extends substantially parallel to the surfaces of the first and second mirrors such that respective light beams deflected by the first mirror and the second mirror are out of phase with respect to each other by a deflected phase difference; a first photosensitive member configured to receive the first light beam reflected by the first mirror of the beam deflector, a first image being formed on the first photosensitive member; a second photosensitive member configured to receive the second light beam reflected by the second mirror of the beam deflector, a second image being formed on the second photosensitive member; and a transfer medium configured to receive the first image from the first photosensitive member and the second image from the second photosensitive member, wherein the first light beam and the second light beam having a timing difference therebetween such that, when the first and second images are respectively transferred onto the transfer medium, the transferred second image overlaps with the transferred first image substantially in phase, and wherein a distance between the first photosensitive member and the second photosensitive member along a sub-scanning direction of the image forming apparatus corresponds to an odd multiple of half of a distance the transfer member travels during a pivot period of the beam deflector during which the double mirror portion range of its pivoting motion.