| 摘要 |
PROBLEM TO BE SOLVED: To obtain an image forming device that defective transfer such as transfer omission is not caused and a recording sheet is prevented from being defectively separated from a photoreceptor drum by the effect of the moisture absorbing amount of the recording sheet. SOLUTION: The humidity of outside air is measured by a humidity sensor 300. Based on measured humidity information, the moisture absorbing degree of the recording sheets S placed on a manual feeding tray 10 is presumed by a CPU 400. Based on the presumed moisture absorbing amount, transfer bias and separation voltage are optimally set. The sensor 300 is installed at the side wall of an image forming device main body A above the tray 10. Then, the humidity of the outside air taken in through a slit formed at the side wall is measured by the sensor 300. |
