A forming unit forms a latent image of input image data. A counter counts number of times of forming the latent image in a sub-scanning direction, in which an upper limit of the number of times is set. A first control unit controls the forming unit to form the latent image based on the upper limit. A determining unit determines whether a latent image forming is performed by the forming unit exceeding the upper limit. When the determining unit determines that the latent image forming is performed exceeding the upper limit, a second control unit controls, the forming unit to continue to form the latent image.