Patent ID: 7618128

Claim:
A liquid ejection apparatus, comprising: a liquid ejection head including: a nozzle through which liquid is ejected, a pressure chamber which stores the liquid ejected through the nozzle, a pressurizing device which changes a volume of the pressure chamber to apply pressure to the liquid stored in the pressure chamber, and a supply port through which the liquid is supplied to the pressure chamber; and a drive controlling device which drives the pressurizing device so as to increase the volume of the pressure chamber more than the volume of an initial state thereof before starting an ejection operation for a predetermined period of time after the liquid is ejected through the nozzle, and to return the volume of the pressure chamber to the initial state after the predetermined period of time elapses, wherein the liquid ejection head has a structure such that inertance Mn of the nozzle, liquid resistance Rn of the nozzle, compliance Cn caused by a surface tension of the liquid in the nozzle, inertance Ms of the supply port, and liquid resistance Rs of the supply port satisfy the following inequality: 4 · ( Mn + Ms ) Cn ≦ ( Rn + Rs ) 2 , so that oscillation of a meniscus surface located in vicinity of the nozzle is controlled at a time of refill when the liquid is filled in the pressure chamber through the supply port after the liquid is ejected from the nozzle, the pressurizing device is responsive to a voltage level of a drive signal, at the end of the ejection operation, the voltage level of the drive signal immediately changes to a voltage level, different from the voltage level at the end of the ejection operation, at which an operation to return the volume of the pressure chamber to the initial state begins, the liquid has a viscosity of at least 5.5×10 −3 Pa·s, and a volume ΔV which is obtained when increasing the volume of the pressure chamber from the initial state thereof before starting the ejection operation for the predetermined period of time after the liquid is ejected through the nozzle, satisfies the following inequality: Δ ⁢ ⁢ V ≦ 2 3 · π · r 3 , where r is a radius of the nozzle.