Patent ID: 8437033

Claim:
An optical scanning device, comprising: plural light sources that emit light beams corresponding to images using developing agents each having different brightness; a deflector that deflects plural light beams emitted from the plural light sources as the plural light beams go incident on a same reflection surface thereof at different angles of incidence in a sub-scanning direction; and plural reflection members that reflect the plural light beams deflected by the deflector to be distributed to surfaces of different photoconductors, wherein, of light paths of the plural light beams, a number of the reflection members that are disposed in a light path of a light beam corresponding to an image using a developing agent having highest brightness is larger than the numbers of the reflection members that are disposed in light paths of the light beams corresponding to images using the other developing agents, wherein the plural light sources include: a first light source that emits a first light beam corresponding to an image using a cyan developing agent; a second light source that emits a second light beam corresponding to an image using a magenta developing agent; a third light source that emits a third light beam corresponding to an image using a yellow developing agent; and a fourth light source that emits a fourth light beam corresponding to an image using a black developing agent, wherein the reflection members include: at least one first folding mirror that reflects only the first light beam; at least one second folding mirror that reflects only the second light beam; at least one third folding mirror that reflects only the third light beam; and at least one fourth folding mirror that reflects only the fourth light beam; wherein the at least one third folding mirror comprises more of the reflection members than the number of the reflection members that comprise the at least one first folding mirror, the number of the reflection members that comprise the at least one second folding mirror and the number of the reflection members that comprise the at least one fourth folding mirror, and wherein the third folding mirror reflects the third light beam so that a difference in light beam intensity between the center portion and the end portion of the image height of the third light beam is larger than a difference in light beam intensity between the center portion and the end portion of each image height of the first, second and fourth light beams.