| 摘要 |
PURPOSE: To minimize the remaining time of dampening fluid and to prevent contamination by providing control means for limiting the amount of the dampening liquid staying in a nip and the adjoining area and limiting the amount of the fluid overflowing from the area. CONSTITUTION: A pan roller 2 is provided widthwise to the printer and plural manifolds 13 for feeding dampening fluid are provided longitudinally to the pan roller 2. Plural sensors 4 are arranged with intervals longitudinally to the pan roller 2, and signals are sent to a valve drive device through a multiplexor and threshold detector. Control zones are divided into 4 zones. The sensors 4 consist of grouped parallel conductivity probes and are arranged along the axis core of the pan roller 2. When an excess amount of dampening fluid exists in the position of the sensors 4 connected by the multiplexor, resistance between the parallel probes of the sensors 4 is lowered, the control action of the system is not started and the dampening fluid is not supplied to the nip. When an overflowing condition is not detected by the sensors 4, the control action is started. |
