| 摘要 |
PURPOSE:To provide the titled device which drives an ink head by a comparing output between each threshold of threshold matrices different in random numbers and an input picture signal including gradation information based on uniform density characteristics, and can print a picture faithful to gradation of the input picture signal. CONSTITUTION:A maximum level of gradation in an input picture signal Vij is set as a maximum value of print density, and a pattern of a threshold matrix 2 is determined based on uniform density conversion characteristics into which it is equally divided at each gradation. A comparing output Rij from a comparator 1 is converted into a jet signal by a head drive circuit 4 via a picture element memory 3, and ink drops 6, 6... are jetted by driving an ink head 5. |
