To control by a simple constitution a position on a time axis of a pulse signal which drives an electro-optic element.

The electro-optic element E has its tone controlled according to a drive signal Xi. An I/F circuit 28 acquires image data D[1]-D[n]. A unit circuit U of a driving circuit 24 generates the drive signal Xi to be a driving current iDR for a time before a time length according to a numerical value passes after a starting point of a unit time T if the numerical value of the image data D[i] acquired by the I/F circuit 28 belongs to a numerical value group G1. The unit circuit U generates the drive signal Xi to be a driving current IDR for a time up to a time point precedent by the time length according to the numerical value from an end point of the unit time T if the image data D[i] belongs to a numerical value group G2.