Patent ID: 8807680
Filing Date: 2014-08-19
Classification: B41J

Abstract:
1. A method for driving a piezoelectric element of a liquid-droplet ejection head including: a plurality of piezoelectric elements each interposed between corresponding two electrodes of a plurality of electrodes; and a plurality of nozzles respectively corresponding to the plurality of piezoelectric elements, the liquid-droplet ejection head being configured to apply a drive voltage to one of the plurality of piezoelectric elements to eject a liquid droplet through a corresponding one of the plurality of nozzles, the method comprising: a first step of increasing a voltage of a power source to a reference voltage level; and a second step of charging one electrode of the two electrodes to the reference voltage level by repeating a plurality of source-connections and a plurality of source-disconnections between the power source and the one electrode while keeping the voltage of the power source at the reference voltage level, such that a ratio of a connection time of each of at least one of second and subsequent connections of the plurality of source-connections to a disconnection time of a corresponding one of at least one of the plurality of source-disconnections which one is continued from said each of the at least one of the second and subsequent connections is greater than a ratio of a connection time of a first connection of the plurality of source-connections to a disconnection time of a disconnection of the plurality of source-disconnections which is continued from the first connection.