PURPOSE: To ensure the print area of black stripes by adjacent print letters, by providing the print letters for bar code of required types of required column at the external circumference of the print drum and locating nonprint section for print letter's share at one side adjacent to specific print letters.

CONSTITUTION: The 7 types of bar code element print letters 20 printing each data character are located at the external circumference of the print drum, and the respective element print letter is formed with the combination of the convexed black stripe print section 20a and the concaved white stripe print section 20b. Further, the print 20a of each element print letter 20 is formed with 2 or 3 modules so that sharp print can be made with a small print force. Further, the difference of area of the print 20a of the element print letter 20 is taken as one module's share so that different print pressure per unit area due to the print hammer can be avoided, due to the types of the element print letter 2. Further, at the right the virtual space 20c corresponding to nonprint area for one module's share is located to ensure the print area of the print 20a of the adjacent element print letters 20.