Patent attributes
An ink jet head driver including a control section that calculates a first head passing time required for the paper sheet from the leading edge to the tailing edge to pass the ink jet head, drives the piezoelectric element of the ink jet head for a predetermined time to perform precursor microvibration immediately before a leading edge of the paper sheet reaches right under the ink jet head and then drives the piezoelectric element according to the normal pixel data to form the image on the paper sheet when the first head passing time is under the deterioration time of the ink, and drives the piezoelectric element of the ink jet head for a predetermined time to perform precursor microvibration immediately before the leading edge of the paper sheet reaches right under the ink jet head.
