| 摘要 |
PURPOSE:To bring an air flow from an air outlet into a constant velocity, by a method wherein the air pressure in an air feed path is held in a constant value through a special control of the air pressure in an air feed path, through which the air flow is jetted from an air outlet positioned facing to an ink outlet. CONSTITUTION:An air feed path 16 is provided with a pressure sensor 25, a control signal generating circuit 26 and a pump drive circuit 27. When the air pressure in the air feed path 16 is higher than the given pressure, an air pump 14 is reduced a drive voltage, and if lower than the given pressure, the air pump 14 is increased the drive voltage. This enables to prevent a change of the air pressure in the air feed path due to a change of a performance of an air feed source and a pressure regulating valve. |
