Patent ID: 7924303

Claim:
A method for controlling a line head including a focusing optical system, first light emitters, light from which being focused by the focusing optical system, second light emitters disposed next to the first light emitters in a first direction, light from the second light emitters being focused by the focusing optical system, and third light emitters disposed next to the second light emitters in the first direction, light from the third light emitters being focused by the focusing optical system, the method comprising: turning on the first light emitters at time t 0 ; turning on the second light emitters after a period t 1 has passed since the time t 0 ; and turning on the third light emitters after a period t 2 has passed since the time t 0 , wherein the periods t 1 and t 2 are controlled under a following condition: t 2 ≠n×t 1 (n is an integer two or greater), first latent images formed by the first light emitters at the time t 0 on a scanned surface that moves in the first direction, second latent images formed by the second light emitters after the period t 1 has passed on the scanned surface that moves in the first direction, and third latent images formed by the third light emitters after the period t 2 has passed on the scanned surface that moves in the first direction are formed in a second direction perpendicular to or substantially perpendicular to the first direction, and a distance between the first latent images and the second latent images is a non-integral multiple of a width of any of the first latent images in the second direction.