LIQUID DROPLET DISCHARGE HEAD AND IMAGE FORMING APPARATUS EQUIPPED WITH THE SAME

PROBLEM TO BE SOLVED: To provide a liquid droplet discharge head which can reduce a waste liquid amount because of preliminary discharge after suppressing an increase in viscosity of a liquid near a nozzle, and to provide an image forming apparatus equipped with the same. SOLUTION: The liquid flowing to an ejector through a first fluid flow channel 51 and from the ejector to a second fluid flow channel 53 circulates by vertical driving mechanisms 140 and 142. A liquid viscosity-increase preventing controlling part 162 changes a circulation amount of the ink that flows in the ejector between at the time of liquid droplet discharge and at the time of waiting for liquid droplet discharge. At the time of liquid droplet discharge, the circulation amount is set to a level which has no effect on liquid droplets delivered from the nozzle. At the time of waiting for liquid droplet discharge, the circulation amount is set taking a limit and the like of an output of the vertical driving mechanisms 140 and 142 into consideration. The circulation amount can be optimized by changing the circulation amount of the liquid between at the time of liquid droplet discharge and at the time of waiting for liquid droplet discharge. Therefore, the frequency of preliminary discharge can be reduced after the increase in viscosity of the liquid near the nozzle is suppressed. Hence the waste liquid amount because of preliminary discharge can be reduced. COPYRIGHT: (C)2009,JPO&INPIT