| 摘要 |
PURPOSE:To maintain a uniform printed density even when printing at high speed, by a construction wherein one end of each heating element is connected to a switching element, while the other end is connected to a common terminal, and the common terminal is connected to a power source through a special resistance element. CONSTITUTION:One end of each of a plurality of heating elements 2 arranged in a thermal head 3 is connected to a current passage controlling circuit 8 and the power source 4 through the switching element 1, while the other end is connected to the common terminal, which is connected to the power source 4 through a positive temperature coefficient resistance element 10 the temperature of which is raised through self-heating. |
