Droplet discharge device and method for driving droplet discharge head

摘要

A droplet discharge device having a droplet discharge head provided with a plurality of nozzles that discharge droplets; a plurality of pressure chambers communicating with the nozzles; and a plurality of pressure generating units for changing a capacity of each pressure chamber by applying a drive signal. The drive signal includes an expansion pulse and a contraction pulse, and the plurality of nozzles are divided into a plurality of groups each comprising one or more nozzles. A drive voltage value of the expansion pulse is set to be common to the respective groups. The drive signal which has a drive voltage value of the contraction pulse independently set in accordance with a droplet speed level for each group is applied to the droplet discharge head, and the droplets are discharged.

主权项

1. A droplet discharge device comprising:
a drive signal generation circuit which generates a drive signal; and a droplet discharge head which includes:
a plurality of nozzles that discharge droplets;a plurality of pressure chambers communicating with the nozzles; anda plurality of piezoelectric material substrates that change a capacity of each pressure chamber by application of the drive signal which is generated by the drive signal generation circuit, wherein:
the drive signal generation circuit is configured to generate the drive signal which includes an expansion pulse to expand the capacity of each pressure chamber and a contraction pulse to contract the capacity of each pressure chamber,the plurality of nozzles are divided into a plurality of nozzle groups each comprising one or more nozzles and corresponding to the piezoelectric material substrates,the drive signal generation circuit is configured to generate the drive signal such that a drive voltage value Von of the expansion pulse is set to be common to the respective groups and such that a drive voltage value Voff of the contraction pulse is independently set in accordance with a droplet speed level for each group, the drive signal is applied to the droplet discharge head, and the droplets are discharged,the expansion pulse expands the capacity of each pressure chamber from a predetermined reference state and then restores the capacity to the reference state, and the contraction pulse subsequently contracts the capacity of each pressure chamber and then restores the capacity to the reference state, andthe drive voltage value Von of the expansion pulse and the drive voltage value Voff of the contraction pulse are set such that |Von|/|Voff| is not less than 1 and not more than 2, where the drive voltage value Von of the expansion pulse is a voltage corresponding to a difference from a reference voltage applied in the reference state, and the drive voltage value Voff of the contraction pulse is a voltage corresponding to a difference from the reference voltage.