Patent ID: 7416268

Claim:
A drive circuit which drives a plurality of piezoelectric elements connected in a matrix connection, each of the piezoelectric elements having a first electrode and a second electrode, the drive circuit comprising: a drive signal generating device which generates a drive signal with voltage of a single polarity to be applied to the piezoelectric elements; a drive controlling device which controls a timing for applying the drive signal to each of the piezoelectric elements; and a plurality of switching devices which apply the drive signal to the piezoelectric elements according to control of the drive controlling device, a number of the plurality of switching devices being smaller than a number of the plurality of piezoelectric elements, wherein the drive controlling device applies a composite drive signal to one of the piezoelectric elements to successively operate the one of the piezoelectric elements in directions opposite to each other by setting the second electrode of the one of the piezoelectric elements to a reference potential while applying the drive signal with voltage of the single polarity to the first electrode of the one of the piezoelectric elements and then setting the first electrode of the one of the piezoelectric elements to the reference potential while applying the drive signal with voltage of the single polarity to the second electrode of the one of the piezoelectric elements in succession.