PURPOSE: To contrive to enhance processing speed, by providing a gate for inhibiting the supply to a printing mechanism of serial data obtained through a parallel-to-serial converting circuit for an amount counted by a counter, when insertion of a pitch between characters is designated by a register.

CONSTITUTION: Outputting of a character pattern from a character pattern generator is started, a character pattern for one character is set into the parallel-to- serial converting circuit 16, and is converted into serial dots. At this time, when it is confirmed from the content of a specified bit in a printing modifying information register 11 that insertion of a pitch is designated for the character in a Chinese character mode, an AND condition is established at an AND gate 13. Simultaneously, the number of dots to be added is set from a RAM12 into a counter 15, and an output from the counter 15 becomes effective when parallel-to-serial conversion for a one-character amount of data is completed. Then, a NAND gate 14 and an AND gate 17 function to inhibit the output of the circuit 16, and outputs 0 data to the printing mechanism as serial dot data.