| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that in a cleaning process in which an electrochemical reaction is applied to a material layer in a surface of a thermal action portion to elute the material layer for removing kogation deposited on the surface of the thermal action portion in a liquid chamber of a liquid ejection head, variations in the conductivity of the liquid cause the elution quantity to change thereby bringing about deterioration of printing quality due to insufficiently removed kogation and shortening of head service life due to excessive elution.SOLUTION: Cleaning under appropriate cleaning conditions is performed by disposing an electrode pair 141A, 141B for measuring conductivity in the same liquid chamber as that of a material layer (i.e., an upper electrode 131) of a surface of a thermal action portion to be eluted, and measuring conductivity of a liquid using the electrode pair before kogation is removed. |
