| 摘要 |
PURPOSE:To stabilize development by providing a means which detects developer coating unevenness on a developing sleeve and eliminates the coating unevenness automatically. CONSTITUTION:When a coat layer has normal thickness, almost all of LED light is absorbed and not detected because a developer is black, but the LED light is reflected by a developer sleeve surface where the coat layer becomes thinner owing to coating unevenness, so a phototransistor positioned over said part detects that. At this time, the detection signal of a comparator 14 which compares the detection output of the phototransistor with a reference value is transmitted to a motor driving circuit 13, which moves a sweeper 8 forth and back once in the generating-line direction of the developing sleeve 2, so a motor 11 receives the output of the motor driving circuit 13 to rotate. Thus, the gap (g) between the developing sleeve 2 and a blade 3 is cleaned to eliminate blocking, so the coating unevenness is eliminated. Consequently, stable development is carried out. |
