| 摘要 |
PURPOSE:To prevent ink drops from being unstably discharged due to unnecessary vibration at the top of a head, by setting the length from an orifice to the tip of the ink ejection part of an electro-mechanical converter mechanically coupled with a pressure chamber, not larger than the mean inside diameter of the pressure chamber. CONSTITUTION:An electro-mechanical converter 5 is coupled with a pressure chamber 3 located between an orifice 6 and an ink feed unit 4. The length l from the orifice 6 to the orifice-side end face 7 of the converter 5 is set not larger than the mean inside diameter d of the pressure chamber 3. If the length l is set at about five times of the mean inside diameter d, the direction of discharge of ink is disturbed and many satellites are produced due to vibration. When the length is equalized to the mean inside diameter, the influence of the vibration is greatly reduced. When the length is equal to 1/2-1/3 of the mean inside diameter, the most stable and reliable printing property is attained. If the length is equalized to zero, the discharge performance of the ink greatly decreases due to ink leakage on the tip. |
