| 摘要 |
PURPOSE:To prevent the rise of a fogging level by correcting a development bias. CONSTITUTION:Before process control is done, the fogging level is detected and a development bias is corrected. After a photosensitive body 4 is electrified, destaticization is carried out with a blank lamp 22; at this time, while varying the development bias, the density of the fog is checked with a toner sensor 30. The relation between the development bias and the fog is found by the use of the value obtained by this, and the fogging level at the time when toner is not attached is determined. When the fogging density is higher than a reference value, the value which is obtained by adding 40V to the value of the fogging level, is applied to a developing roller 28 as a development bias voltage, and copying is carried out. |
