Methods, systems, and apparatuses, including computer programs encoded on computer-readable media, for receiving a timing signal at a first access point, wherein the timing signal is also received at a second access point. The light scanning device scans the photosensitive drum 13 with the light beam L1 and set scanning timing of the photosensitive drum 13 using the light beam L1 based on detection timing of the light beam L1 using the BD sensor 72. The lens holder is mounted on the seat between the two sidewalls. The controller then re-engages the fan load when engine speed is approximately equal to the desired speed or when a maximum disengagement time has elapsed.