| 摘要 |
PURPOSE:To make the density of transfer constant regardless of the change of temperature environment by inserting a thermistor having a temperature gradient, of which the gradient of the temperature characteristic curve of a thermal transfer ink ribbon is brought to zero, into a thermal head drive circuit. CONSTITUTION:Thermal heads 1, 2 are connected to the thermistors 5, 6 each inserted to the power supply side through switches 3, 4. The thermistors 5, 6 are ones severally connected to the thermal heads 1, 2 of points 12, 10, and have different resistance value and temperature gradients. When printing signal input 10 is inputted, a control circuit 11 transmits the code signal of a character to be printed to a character generator 9, and output corresponding to a dot pattern is obtained. An output signal drives the thermal head 1 through a driver 8. Each dot is driven through the thermistor 5 correcting the temperature characteristic curve in the direction that the gradient is brought to 0 at that time. |
