| 摘要 |
PURPOSE:To simply and accurately detect the pattern shift of heating elements and electrodes by providing a dummy pattern measuring the pattern shift of a plurality of the heating elements and the electrodes to a thermal head. CONSTITUTION:In such a state that electrodes 4 are shifted to the left with respect to the heating elements 3 of a dummy pattern 10, the heating elements 3 and individual electrodes 4b are overlapped within the range of about 90% in the laterial direction of the heating elements 3. When voltage is applied across a common electrode 4a and the individual electrodes 4b in this state to measure the resistance values of the heating elements 3, the resistance values of the heating elements 3 become smaller than those at a normal time because the overlap range of the heating elements 3 and the individual electrodes 4b becomes wider than that at a normal time and, therefore, pattern shift can be detected. Since the pattern shift of the heating elements 3 and the electrodes 4 is detected by measuring the resistance values of the heating elements, this pattern shift can be simply and accurately detected. |
