Patent ID: 8141973
Filing Date: 2012-03-27
Classification: B41J

Abstract:
1. A liquid droplet ejection head comprising: an ejector including a nozzle for ejecting a liquid droplet, a pressure chamber communicating with the nozzle through a communication path, and an actuator for applying pressure to a liquid in the pressure chamber; a first fluid flow path in which the liquid supplied to the pressure chamber of the ejector flows; a second fluid flow path into which the liquid supplied from the first fluid flow path to the pressure chamber flows through the communication path; a liquid viscosity-increase prevention structure for preventing an increase of viscosity of the liquid in the ejector, the liquid viscosity-increase prevention structure being a circulation unit for circulating the liquid to the ejector through the first fluid flow path, and from the ejector through the second fluid flow path; and a liquid viscosity-increase prevention controller for changing the operation frequency of the liquid viscosity-increase prevention structure between when the liquid droplet is ejected from the nozzle and when ejection of the liquid droplet is paused and no liquid droplet is being ejected from the nozzle, the liquid viscosity-increase prevention controller changing the amount of circulation of the liquid flowing in the ejector by controlling the circulation unit when the liquid droplet is ejected from the nozzle and when ejection of the liquid droplet is paused.