INK SUPPLY MECHANISM OF ON-DEMAND TYPE INK JET PRINTER

摘要

PURPOSE:To provide an ink supply mechanism of an on-demand type ink jet printer capable of always printing under satisfactory condition by keeping the internal pressure of a sub-ink tank in a carrier at a constant level. CONSTITUTION:A sub-ink tank 6 which temporarily stores ink is installed on a carrier 11 and air 7 is sealed there with the ink. In addition, a pressure sensor 8 is provided and the ink of the sub-ink tank 6 is increased by an ink supply pump 4. At the same time, the pressure of the sealed-in air increases. If the pressure sensor 8 detected that an increase in the pressure has reached a set pressure level, the drive of the supply pump 4 is stopped to terminate the ink supply. In addition, the flowback of ink in a supply tube 3 due to the existence of an internal pressure in the sub-ink tank 6, is prevented by a check valve 5. During printing, this process is sequentially performed, making it possible to carry out satisfactory printing all the time.