| 摘要 |
PURPOSE:To reduce the size of a piezoelectric element without adverse effects such as a rise in a driving voltage and to contrive a reduction in the size of a printing head, by a construction wherein the acoustic capacity of a vibration system consisting of a piezoelectric element and a vibrating plate is set to be not higher than a specified value, and the inertance and acoustic resistance of liquid-ejecting passage are limited. CONSTITUTION:In the equivalent electric circuit of a printing head shown, (m) is inertance, c is acoustic capacity, r is acoustic resistance, 10 is the vibration system consisting of the piezoelectric element 11 and the vibrating plate 12, 1 is a pressure chamber, 2 is a supplying part and 3 is a nozzle part. Generally, the ink droplet diameter D1 is preferably about 50-150mum, and particularly in the case of high-density printing such as the case of 24 nozzles, an excessively large droplet diameter is unfavorable in view of printing quality. When m3 and r3 expressed in mks units of the SI system satisfy the relationship r3>10<4>Xm3, ink droplets with a diameter of not larger than 150Xm can be ejected, and the value of C0 which gives the minimum voltage is in the range of 1X10<-18>m<5>/N<=C0<=9X10<-17>m<5>/N. |
