| 摘要 |
In the ink jet printer, a pressure generation chamber 11 is expanded in a stepped manner, which enables a high speed discharge of a very small ink droplet. Prior to the ink discharge, the pressure generation chamber 11 is contracted so as to enable a high-accuracy gradation printing with a wide range of ink droplet size. A control unit 20 generates: a first contraction signal V 1 for contracting the pressure generation chamber 11 without discharging any ink droplet 17; a first expansion signal V2 for expanding the pressure generation chamber 11 to discharge the ink droplet 17; and a second contraction signal V3 after the first expansion signal V2, so as to deform the electro-mechanic converter 15 to temporarily contract the pressure generation chamber 11, thus increasing the speed of the ink droplet discharge from the nozzle 12. |
