Patent ID: 8474931

Claim:
A printing apparatus which prints on a printing medium by supplying ink from a first container, that is formed from an electrically insulating member and contains pigment ink containing a solvent and pigment particle different in permittivity, to a printhead, comprising: a thin plate-like first electrode which is arranged to contact an outer surface of the first container; a thin plate-like second electrode which is smaller in surface area than said first electrode, and is arranged to face said first electrode and contact an outer surface of the first container such that said first and second electrodes sandwich the first container; a power supply unit configured to apply an AC voltage to said first electrode and said second electrode; a detection unit configured to detect an interelectrode voltage between said first electrode and said second electrode under a condition where the AC voltage is applied by said power supply unit to said first electrode and said second electrode; and a control unit configured to control to stop application of the AC voltage from said power supply unit based on the interelectrode voltage detected by said detection unit.