| 摘要 |
<p>PURPOSE:To make it possible to prevent a thermal head from being broken by judging whether the current temperature is a temperature at which a line thermal head is to be operated for color development, based on an output pulse from an oscillation circuit the oscillational pulse period of which varies with temperature. CONSTITUTION:Before starting color development by operating a line thermal head 1, it is necessarily judged by a high temperature discriminating means 4 whether the color development by the head is to be performed. When it is judged that the color development is not to be performed, the color development by the head is stopped by a head color development stopping means 5, and the color development is suspended by a head color development suspending means 6 until it is judged by the means 4 that the color development by the head is to be performed. When it is judged by the means 4 that the color development by the head is to be performed, a color developing time for the head is determined by a head color development time determining means 7, and the color development by the head 1 is effected by a head color developing means 8.</p> |
