| 摘要 |
PROBLEM TO BE SOLVED: To obtain uniform printing quality without irregularity in printing by varying the regulating position of a doctor blade regulating the height of the magnetic brush of developer attracted to a magnetic roll and fixing the height of the brush or attracted amount even when the bulk density or the electrified amount of the developer in the midst of printing is changed. SOLUTION: In this device, the two-component type developer 3 is stirred by a stirring screw 6, attracted and carried in a brush state on the magnetic roll 4; and a latent image on a photoreceptor drum 7 is developed by the magnetic brush whose height is regulated to a specified value by a doctor blade 5. The device is provided with a pressure sensor 19 for detecting the bulk density of the developer, a coupling member 15 supporting the doctor blade 5 so that it can turn centering the shaft of the opposed roll 4 in parallel along the outer peripheral surface of the roll 4 in accordance with output which is the signal of the bulk density of the developer detected by the sensor 19 outputted through a control circuit 18, and a turning control means consisting of a gear part 16 and a driving motor 17. |
