Patent ID: 8123330
Filing Date: 2012-02-28
Classification: B41J

Abstract:
1. An ink jet head cleaning method for removing kogation deposited on an upper protective layer in an ink jet head, wherein the ink jet head has: an electrothermal transducer portion arranged in an ink path communicating with an ink ejection orifice, an insulating protective layer to prevent contact between the electrothermal transducer portion and an ink in the ink path, and an upper protective layer having a heat application portion, the heat application portion covering at least a portion heated by the electrothermal transducer portion of the protective layer, wherein the upper protective layer is formed of a material containing a metal which is dissolved by an electrochemical reaction with the ink and which does not form, on heating, an oxide film which will hinder the dissolution; the cleaning method comprising the step of: using the upper protective layer as one electrode to cause the electrochemical reaction and thereby dissolve the upper protective layer in the ink, wherein a voltage application to the upper protective layer to cause the electrochemical reaction is performed in connection with an ink discharging operation that discharges the ink from the ink ejection orifice.