Patent ID: 8310514

Claim:
A control method of a line head including: a first image forming system; a first light emission element which emits light for forming an image by an image forming lens of the first image forming system; a second image forming system disposed in a first direction of the first image forming system; and a second light emission element which emits light for forming an image by an image forming lens of the second image forming system, the method comprising: when the first light emission element emits light at a time t 0 and then emits light after a time t 1 from the time t 0 , and also when the second light emission element emits light after a time t 2 from the time t 0 , controlling the time t 1 and the time t 2 such that t 2 ≠n·t 1 (n: 2 or larger integer) holds, wherein a first spot pitch between a first latent image formed on a scanned surface shifting in the first direction when the first light emission element emits light at the time t 0 and a second latent image formed on the scanned surface when the first light emission element emits light at the time t 1 is a value non-integer times larger than the spot diameter of a latent image formed on the scanned surface by the first light emission element.