PURPOSE:To simplify the form designing by distributing a character matrix at the center of the printing line to print. CONSTITUTION:A counter 2 is subtracted by 1 each time the reading of a line buffer 1 ends with respect to one scan starting pulse of the line buffer 1. The value A will be an input to a comparator 6 and a comparator 7. B=(1-h)divided by 2+h is applied to the other input of the comparator 6. A dot transfer circuit 10 sends dot information of 0 indicating blank to a printing section 12 when A>B in the output of the comparator 6 and specified dot information thereto at the address of a matrix memory 11 as given from a decoder 4 when A<=B. D=(1-h)divided by 2 is applied to the other input of the comparator 7 and dot information of 0 is sent to the printing section 12 when A<=D. Then, when the value of the counter 2 makes 0, the printing of the line buffer 1 is completed.