| 摘要 |
PROBLEM TO BE SOLVED: To discharge an aimed droplet by eliminating the residual electric charge of liquid after the discharge of a droplet, and to perform precise control of the discharge of the droplet while reducing a device cost.SOLUTION: There is provided a light response element 34 which has one terminal electrically connected between a discharge electrode 12 and a light response element 31, and the other terminal electrically connected to a low-potential terminal or grounded, or grounded. The light response element 34 is irradiated with light from a light emitting element 35 to be decreased in a resistance value of the light response element 34, and the discharge electrode 12 is electrically connected to the low-potential terminal or grounded to make a short circuit between the discharge electrode 12 and a high-voltage source 42. When the discharge of a droplet is turned to non-discharge, at least the irradiation of the light response element 34 with the light is turned on. The light response element 34 is decreased in the resistance value to electrically connect the discharge electrode to the low-potential terminal side or to ground the discharge electrode 12, and consequently electric charges imparted to the liquid in a liquid chamber during the droplet discharge and remaining after the droplet discharge are discharged to a low potential side or the ground through the discharge electrode 12 and light response element 34. |
