Laff, Whitesel, Conte & Saret
On demand type ink-jet print head having fluid control means
 An on-demand type ink-jet print head requires only a small amount of energy for the droplet formation. A pressure chamber is filled with ink and a transducer or electromechanical conversion element applies a pressure on the ink pressure chamber. A fluid rectifier element (here, a check valve) is provided between the ink supply inlet and the pressure chamber so that a forwardly directed resistance is applied to ink flowing from the ink supply inlet to the pressure chamber and a reversely directed resistance is applied to ink flowing from the pressure chamber to the ink supply inlet. A fluid resistance element (here, a plate with many pinholes) is provided between the pressure chamber and the nozzle. The resistance of the fluid resistance element is greater than the forwardly directed resistance of the rectifier element. 
NEC Corporation
B
B41J
inventional
Michihisa Mitsuo
Suga Tsuzuki