| 摘要 |
PURPOSE:To enable a hollow needle to be connected to a signal line easily when the hollow needle is used as an ink end electrode and design a hollow needle fixing device which is of a simple structure and made at low cost. CONSTITUTION:An ink tank 7 communicates with a recording head 3 through a hollow needle 5 introduced in an ink chamber 11 provided at the lower end. In this ink tank 7, a porous material 6 which absorbs water ink is stored and also one electrode S1 is arranged at a part of the tank with the other electrode S2 being the needle 5. The end of the ink which is output is detected by measuring variations in the resistance between both electrodes beyond the level of a setting value. In addition, the ink tank 7 is equipped with a needle seat 20, with a hole diameter which is almost the same as the outer diameter of the hollow needle 5, for fixing the needle 5 and a fixed shaft member 19 which engages with the needle seat 20 and crosses almost directly the axial direction of the hollow needle 5 in a state where the member 19 is pressed against the hollow needle 5. Further, the fixed shaft member 19 acts as an external connection terminal of the hollow needle 5 which works as the electrode S2. |
