| 摘要 |
PURPOSE:To secure optimum toner layer thickness through simple operation and to obtain an excellent picture regardless of an environmental change, by varying the specified angle of a magnetic blade to internal magnetic poles in a developing sleeve. CONSTITUTION:The magnetic blade 5 is arranged facing an internal magnetic pole 2b with a gap g1 to a nonmagnetic sleeve 3 and tilts forward and backward around a fitting shaft 5a to vary its specified angle, distributing magnetic flux concentration to before and behind the blade 5. When the charge of toner 7 decreases owing to an environmental change to decrease the toner layer thickness and picture density, the blade 5 is set on the downstream side to distribute the magnetic flux concentration to the downstream side, and the toner is allowed to enter to the blade 5 easily, recovering the density by increasing the thickness of the toner layer. When the toner charge decreases, on the other hand, the opposite operations are performed. Consequently, even if temperature of humidity varies, the toner layer thickness is optimized through the simple operation to obtain the excellent picture. |
