| 摘要 |
PURPOSE:To obviate manual setting operation of a device by a method wherein the resistance of a heating resistor in a thermal head is automatically measured, and an electric current having a pulse width determined based on a calculated reference pulse width and the temperature of the thermal head is passed through the thermal head. CONSTITUTION:A system control part 8 transmits an image signal SD to a thermal head 22 line by line, stores image information in a shift register 221, and outputs a latch pulse SL. In this manner, the image information for 1 line is latched in a latch circuit 222. Thereafter, the system control part 8 successively outputs strobe pulses SB1-SB4. The system control part 8 previously stores a reference pulse width correction value corresponding to the temperature in the form of table data or the like, thereby calculating a pulse width in the execution of a recording action while the temperature of the thermal head 22 is detected by a thermister 225. The strobe pulses SB1-SB4 with the calculated pulse width is outputted. Thus, a pulse width is reduced correspondingly to the increase of temperature, a heating energy at a heating resistor 224 is suppressed, and an image recording with an invariably constant density is made on thermal recording paper. |
