| 摘要 |
PURPOSE:To shorten the period of time from the starting of jetting to the time when the jetting becomes stable and enhance the accuracy of jetting by providing an auxiliary pressurizing means between an ink jet head and a pump for supplying an ink. CONSTITUTION:A signal of the ink pressure detected by a pressure detector 18 is converted into a voltage by a detecting circuit 20, the voltage is compared by an error amplifier 21 to a reference voltage fed from a reference power source 22, and a difference signal is fed into a signal generator 23. In accordance with the output of the signal generator 23, a buffle generating power is from a bubble generation driving circuit 24 into electrodes 19. By the bubble generating power fed to the electrodes 19, the volume of a gas layer 13' of the auxiliary pressurizing part 13 is increased through electrolysis of water so as to elevate the pressure of the gas layer 3', thereby regulating the ink pressure. A check valve 16 provided at an ink supplying port 15 is adapted to prevent backflow of ink when the ink pressure in the auxiliary pressurizing part 13 is higher than the pressure at the pump 7, and the above-mentioned gas is automatically released by a pressure reducing valve 17 so as to reduce the ink pressure when the ink pressure in the pressurizing part 13 is excessively high. |
