| 摘要 |
PURPOSE:To reduce dispersion in the heat generation properties of heating resistors to enable a good gradation printing and color printing, by a method wherein, one printing dot is formed by one set of two heating resistors connected in parallel by a discrete electrode, and the heating resistors are continuously formed at the resistor parts. CONSTITUTION:A resistor divided into two parts 21, 22 by grooves 4, 5 is formed between a common electrode 1 and a discrete electrode 31. The resistors 21, 22 are continuously formed at center parts 6. Other discrete electrodes 32, 33 are also similarly constructed. In a thermal print head with such a construction, when a voltage is applied between the common electrode 1 and the discrete electrode 31, an electric current flows mainly through the center parts of the resistors 21, 22 respectively. In this case, because the resistors 21, 22 are not completely independent from each other, the current flows so as to make up for each other. Therefore, a large difference in heating value is eliminated even with some dimensional difference between the resistors 21, 22. In this manner, printing irregularities can be eliminated, and a high-accuracy gradation printing and color printing can be carried out. |
