| 摘要 |
PURPOSE:To satisfactorily prevent the optical fatigue of a photosensitive body with a simple structure without shielding the photosensitive body by providing a means, which detects the time for which a main body part is kept open, and a means which generates a warning signal when this time reaches a certain value. CONSTITUTION:The operation of a timer 22 is started simultaneously with opening of an upper main body 2, and measurement of the time when a photosensitive drum 1 is exposed to the outside is started. When this time reaches a certain time set to the timer 22, that is, when the certain time for which the optical fatigue does not occur before the start of degradation in performance of the photosensitive drum 1 elapses, a timer detection signal is generated from the timer 22. A warning tone is emitted from an indication buzzer 23 based on this timer detection signal and a warning is displayed on a display part 24 based on the timer detection signal to indicate that closing of the upper main body 2 is required. Thus, the optical fatigue of the photosensitive body is prevented. |
