| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device in which the temperature up of a original placing plate is suppressed exactly to a prescribed value or less irrespective of exposure from an illuminating part, the warm-up time of a cooling fan is shortened to the utmost and a cooling power required for the cooling fan is minimized. SOLUTION: When the image forming device (copying machine) 1 recognizes that the temperature of an optical system detected by a temperature detecting means 41 is equal to or more than a prescribed reference value, holds the temperature of the original placing plate 10 to 70 deg.C or less by lengthening the time interval for copying. The number of times of image forming is counted from the initial state, because the thickness of the film of a photosensitive layer is reduced and then the photographic sensitivity of a photoreceptor drum 24 is lowered when the number of times for forming an image on the photoreceptor drum 24 increases. When the total number of counts exceeds 50, 000 times, a control is performed so as to obtain a good image continuously by increasing the exposure from the illuminating part (exposure lamp 12), and compensating degradation of the photographic sensitivity of the photoreceptor drum 24. |
