| 摘要 |
PURPOSE:To increase reliability of an ink check-valve by using a ball. CONSTITUTION:A check-valve consisting of a ball 8 and a ball guide 7 is provided within an ink supply entrance 3, and if a pulse voltage is applied to a piezoelectric body 1, the capacity of an ink chamber 5 instantly decreases and uniform pressure is created within the ink chamber, pushing the ball 8 tightly against the ink supply entrance 3, and the back flow of the ink is prevented. And the ink is discharged only from a nozzle 4 where there is no resistance. When the piezoelectric body 1 restored its normal condition, a negative pressure is created within the ink chamber 5, causing the ball 8 to be released from the ink supply entrance 3 and to stop at where the ball guide 7 is provided, and the ink is supplied into the ink chamber 5. The ball guide 7 is fixed to the wall of the ink chamber 5 around the ink supply entrance 3, and is conically shaped with its top cut off and retains the ball 8 to be able to contact with and released from the supply entrance 3 without deviating from the center. Thus, the function of the back flow valve is accurate and its structure is simplified, resulting in production of a reliable product. |
