Patent ID: 8210665

Claim:
An inkjet printing apparatus comprising: a constant flow valve mechanism comprising: a valve; and a first port, a second port, and a third port in fluid communication with each other through the valve, a portion of the valve being moveable and associated with the first, second, and third ports to produce a change in fluid impedance between the first port and the second port and the first port and the third port, the first port being an input port such that fluid flows from the first port toward the second and third ports; a fluid tank in fluid communication with the constant flow valve mechanism through the first port of the constant flow valve mechanism, the fluid tank being in fluid communication with the constant flow valve through the second port of the constant flow valve; a drop generator in fluid communication with the constant flow valve mechanism through the third port of the constant flow valve mechanism, the drop generator also being in fluid communication with the fluid tank; and an actuator operatively associated with the moveable portion of the valve to change the fluid impedance between the first port and the second port and between the first port and the third port such that the fluid impedance between the first port and the second port changes at the same rate and in an opposite direction as that of a fluid impedance between the first port and the third port.