| 摘要 |
PURPOSE:To make constant the energy impressed on heating resistors and enable to obtain a uniform density, by a method wherein the average resistance of heating resistors in a printing head is outputted as a 3-bit code, and an impressed voltage and the pulse width of a driving pulse are varied. CONSTITUTION:In the printing head 1, three terminals (a)-(c) capable of being strapped to the ground are provided, a binary value indicating a rank number corresponding to a resistance range is set, and the average resistance of a plurality of heating elements is stored. Three-bit information corresponding to the average resistance detected by a resistance-reading part 2 is inputted into a logic part 3 consisting of a micro-computer, a 3-bit code is read, then an impressed voltage or the pulse width of a driving pulse is determined, and the determined value is outputted to a drive-controlling part 4 or a power source part 5. Accordingly, the energy impressed on the heating resistors when pulse- driving by an automatic controlling system can be made to be constant, and printed density can be made to be uniform. |
