PURPOSE: To prevent abnormal operation for a long time by stopping recording processing and informing production of a fault when the count of a count means at the end of forced lighting is not changed before the start of the forced lighting.

CONSTITUTION: A laser scanner unit(LSU) control section 21 of an exposure 20 monitors whether or not a horizontal synchronization detection lighting at a preliminary lighting and between pages is detected by a photodetector prior to the start of recording of a picture by a laser scanning unit(LSU) 22 by counting a photodetection signal outputted from the photodetector. When the count is not increased by the preliminary lighting and the horizontal synchronization detection lighting between pages, it is discriminated that the LSU 22 has a fault to stop the recording processing and the occurrence of a fault is informed by ringing of a buzzer 14 and display onto a display device 15. Thus, when a fault takes place in the LSU 22, the fault is found out early to prevent abnormal operation for a long time.