Liquid-drop discharge device having controlled pressure differential between liquid storage tank and reaction cell

Abstract

A liquid-drop discharge device includes an array of liquid-drop discharge units for discharging liquid from a float cell in communication with a liquid storage tank. A reaction cell, into which fluid is discharged, is provided in communication with the float cell. A differential adjusting tube is provided between the float cell and the reaction cell and includes a release valve for maintaining a specified pressure relationship between an internal pressure P2 of the float cell and an internal pressure P3 of the reaction cell. A driving circuit is provided to drive a pressurizing source of the liquid-drop discharge device and is connected to a control unit. The control unit is connected to a pressure sensor, which detects the internal pressure of the reaction cell and the release valve. The internal pressure P1 of the liquid storage tank is controlled to be larger than the internal pressure P3 of the reaction cell.

What is claimed is:  
     
         1 . A liquid-drop discharge device, comprising: 
 liquid discharge means comprising a plurality of liquid-drop discharge units connected to a common liquid supply path communicating with a liquid storage tank, said discharge units each comprising a piezoelectric/electrostrictive element for pressurizing operations and a pressurizing chamber from which a pressurizing liquid is discharged through a nozzle into a reaction cell having a space into which the nozzles are opened for discharging liquid, wherein P1>P3, with P1 being an internal pressure in the liquid storage tank and P3 being an internal pressure in the reaction cell.    
     
     
         2 . The liquid-drop discharge device of  claim 1 , wherein the internal pressure P1 in the liquid storage tank corresponds to atmospheric pressure.