| 摘要 |
PURPOSE:To always form an excellent image even when the state of an original image or toner is largely changed. CONSTITUTION:The triboelectrification (electrification state) of the toner is largely changed by the change of humidity and the concentration of the toner is largely changed by the triboelectrification of the toner. Based on it, the absolute humidity H is calculated by an arithmetic processing part 42 based on a temperature (t) and the humidity (h) which are detected by an environment detection means 41. The absolute humidity H is compared with the humidity Ht which is previously stored in a memory part 43 by a comparison processing part 45. According to difference between them, a maximum density set value varying means 46 and a transfer current set value varying means 47 are switched. That means, the varying means 46 and 47 are optimally set according to the electrification state of the toner and high image quality is obtained as for image density. |
