| 摘要 |
PURPOSE:To obtain a printed pattern with uniform density, by a method wherein a pulse signal is used for heating an heating resistance element of a heat-sensitive printer, and a temperature control is conducted by detecting the resistance value of the element selectively driven, which detecting is conducted at a timing when the pulse signal is not impressed. CONSTITUTION:When printing is commanded, flip-flop circuits FF1-FFn are set, a gate circuit 2 is opened, a pulse signal S3 for heating is outputted to a driving circuit 3 as a signal S4 from the gate circuit 2, and a signal S5 is generated to selectively drive the heating resistance elements Rh1-Rhn. An analog switch circuit 5 connects the elements Rh1-Rhn and a resistance value detecting circuit 6 to each other at the timing when the output signal S4 becomes L-level and the signal S5 is not impressed on the resistance element driven. The resistance value detected is fed to a Schmidt trigger circuit 7 as a signal S6, and a signal S7 is generated to reset the flip-flop circuits FF1-FFn. Consequently, the gates are closed, the rise in the temperature of the elements Rh1-Rhn is stopped, and the elements are controlled at a predetermined temperature. |
