Ink-jet printer head
AssigneeBrother Kogyo Kabushiki Kaisha
InventorNaoki Katayama
Life of this patent
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Abstract
A measurement electrode for capacitance measurement is disposed so as to be opposed to a common electrode with a second and a third piezoelectric plates in between and to be opposed to all ink pressurizing chambers with a first piezoelectric plate in between. The capacitance of the piezoelectric plate disposed between the common electrode and the measurement electrode is measured with a larger area, and from the measured capacitance, the temperature of the piezoelectric plate is calculated based on the capacitance-temperature characteristic of the piezoelectric plate. In order to generate a pressure suitable for the ink viscosity that changes according to the temperature, the change in the overall temperature of the printer head that changes according to the status of use of the printer is accurately measured.
Claims11
An ink-jet printer head comprising:
- a board where a plurality of ink pressurizing chambers are formed;
- a plurality of piezoelectric plates laminated on the board;
- a common electrode and a plurality of individual electrodes that are opposed to each other with the piezoelectric plates in between, said common electrode being disposed over the ink pressurizing chambers, said individual electrodes being disposed so as to correspond to the ink pressurizing chambers respectively;
- and
- a measurement electrode that is opposed to the common electrode with the piezoelectric plates in between and measures capacitance with the common electrode, said measurement electrode being disposed so as to be opposed to the ink pressurizing chambers.
A piezoelectric actuator having a plurality of displacement portions, comprising;
- a plurality of laminated piezoelectric plates;
- a common electrode and a plurality of individual electrodes that are opposed to each other with the piezoelectric plates in between, said common electrode being disposed over the displacement portions, said individual electrodes being disposed so as to correspond to the displacement portions respectively;
- and
- a measurement electrode that is opposed to the common electrode with the piezoelectric plates in between and measures capacitance with the common electrode, said measurement electrode being disposed over the displacement portions and having substantially the same configuration and area as the common electrode.
Dependencies are inferred from the claim text.