| 摘要 |
PURPOSE:To obtain the multiple nozzle head; wherein flow paths which yield a pressure loss proprotional to the square of a flow speed are provided in the parts of supplying paths that guide ink to a pressuring chamber; and which applies the pressure that is smaller than the pressure applied at the selected time when the half selection is performed and performs the multiplex driving. CONSTITUTION:An example of a four nozzle head is illustrated. In actual cases, however, present invention can be applied to the multiple nozzle head having about 2,000 nozzles. The ink flow paths such as nozzles 3 and pressurizing chambers 2 are formed in the head. Flow paths 13 comprising abruplty expanded parts 11 of the flow paths 13 comprising abruptly expanded parts 11 of the flow paths and abruptly shrunk parts 12 when they are observed from the side of the pressurizing chambers 2, are provided in the parts of supply paths 4. In an equivalent circuit diagram illustrating the head, resistance Rs in the supply path is varied by a volume speed Us of the ink that flows the position. The decrease in the volume speed on the nozzle side is more conspicous than the rate of decrease in pressure phi. When the flow path whose pressure loss is varied in proportion to the square of the flow speed is provided, the flow speed at the time of selection can be made twice the flow speed when the half selection is performed. Thus the speed of the ink droplets can be made fast. |
