| 摘要 |
PURPOSE:To prevent a white streak from being generated between lines, by setting the sum total of pitches of heat generating elements to be 1.005-1.03 times a paper-feeding pitch, and setting the pitch of each of the heat generating elements to be 1-1.3% based on the paper-feeding pitch divided by the number of the heat generating elements. CONSTITUTION:A printing head comprises, for example, 24 heat generating elements 12 arranged in a line in a paper-feeding direction Y, with insulators 12 between the elements 12. The pitches B of the elements 12 are set in the range of 1-1.3% based on a pitch reference value l/n, where l is a paper- feeding pitch and (n) is the number of the elements 12, and the pitches B of at least a part, particularly all, of the elements 12 are set to be greater than l/n. The sum total L of the pitches B is set to be 1.005-1.03 times the paper- feeding pitch l. As a result, a white streak can be prevented from being generated between lines in the case of graphic printing, and it is ensured that ununiformity of printed dots in the case of character printing is slight. Thus, a favorable print output can be obtained. |
