| 摘要 |
PURPOSE:To prevent misprinting from occurring in printing a bar code, without affecting normal recording, by a method wherein abnormality of an heating element is detected by a detector when the element is inoperative, and passing of an electric current to the heating element for detecting the abnormality is performed in the condition wherein thermal energy for recording is not generated. CONSTITUTION:A multiplicity of heating elements 26 for generating thermal energy for recording by selectively passing an electric current to the elements 26 by a selection-controlling circuit 30 are arranged on a line or in a matrix form, and a recording time controlling element 29 turned ON at the time of normal recording is provided on the side of a common terminal for the elements 26. A resistor 32 having a high resistance for passing an electric current in such a range as not to form any color to the heating elements 26 even when the controlling element 29 is turned ON is connected in parallel with the element 29, and a heating element detector 33 comprising a comparator is provided. A reference voltage is given to one of two inputs of the detector 33, while the output side of the controlling element 29 is connected to the other. |
