| 摘要 |
PURPOSE:To enable the optimum image to be obtained only by moving a knob for controlling copy density within the vicinity of the central part of the knob, by changing over the variable width of lamp voltage to a different region in accordance with the sensitivity of a photosensitive drum. CONSTITUTION:It is necessary to control exposure by adjusting variable power 10 or difference of drum sensitivity L, M, H, but to control it with a density control knob 8, necessary displacement width (corresponding to 50-80V lamp voltage) of the knob is made to large because a normal density position (center) is deviated. Therefore, the variable range of lamp voltage is changed over to plural regions, such as low sensitivity width LSW and middle sensitivity width MSW, by providing a snap switch on an operation panel 100, or automatically actuating a switch with the cam of a drum 11 when a drum shaft 12 is inserted into the cam of the drum 11. |
