| 摘要 |
PURPOSE:To prevent the sag of ink from an ink jet head at all times by mounting a check valve between the head and a two-way valve. CONSTITUTION:A check valve 10 is inserted between a two-way valve 9 and a head 1. A two-way valve 6 is ON-OFF controlled by a control signal (a) from a sequence circuit, and the two-way valve 9 is turned ON temporarily. Consequently, the second two-way valve 9 is turned ON immediately after the two-way valve 6 is OFF-operated, the state of negative pressure is formed instantaneously in an ink supply duct up to the ink jet head 1 from the first two-way valve 6, and injection is stopped without generating the sag of ink on the front of a nozzle for the ink jet head 1. Even when the two-way valve 9 is turned OFF and a diaphragm 15 is pushed back in the direction of the arrow B, a push-back to the head side of ink can be obviated by the check valve 10, thus preventing the sag of ink from the head at all times. |
