Patent ID: 9028025
Filing Date: 2015-05-12
Classification: B41J

Abstract:
1. An ink jet head, comprising: a plurality of nozzles; a piezoelectric member having a plurality of driving channels for storing ink, each of the driving channels being in communication with a respective one of the plurality of nozzles, and a plurality of dummy channels alternately arranged with the driving channels; a plurality of first side walls, each disposed between one of the plurality of the driving channels and one of the plurality of the dummy channels, each of the first side walls including a first driving channel side surface of the corresponding driving channel and a first dummy side surface of the corresponding dummy channel; a plurality of second side walls, each disposed between one of the plurality of the driving channels and one of the plurality of the dummy channels, each of the second side walls including a second driving channel side surface of the corresponding driving channel opposed to the first driving channel side surface and a second dummy channel side surface of the corresponding dummy channel opposed to the first dummy channel side surface; a plurality of first electrodes, each provided on the first and second driving channel side surfaces; a plurality of second electrodes, each provided on the first dummy channel side surfaces, wherein when a voltage is applied to one of the second electrodes, the corresponding first side wall is deformed such that a capacity of the corresponding driving channel changes; a plurality of third electrodes, each provided on the second dummy channel side surfaces separate from the second electrodes, wherein when a voltage is applied to one of the third electrodes, the corresponding second side wall is deformed such that the capacity of the corresponding driving channel changes; a signal generating unit configured to generate and apply a precursor signal to the plural second electrodes which causes the first side walls to deform such that ink in the driving channels oscillates, and to generate and apply a driving signal to at least one of the plural third electrodes which causes the corresponding second side wall to deform such that ink in the driving channel is ejected from the nozzle; a plurality of switches configured to electrically connect and disconnect the plural third electrodes to the signal generating unit; and a control unit configured to control each of the plurality of switches based on a selection of one or more of the plurality of driving channels from which ink is to be ejected.