| 摘要 |
PURPOSE:To obtain a thermal head with excellent thermal efficiency, by using as a substrate a crystallized glass enamel layer in which the content of alkaline earth metals in the vicinity of the surface is made higher than that in other parts. CONSTITUTION:A thermal head comprises a steel plate 1, an enamel layer 2, electrodes 3, resistors 4 and an abrasion-resistant layer 5. In the thermal head, the content of alkaline earth metals in a near-surface layer 6 of the enamel layer 2 is set to be higher than that in a deep layer part 7 of the enamel layer 2. Since the alkaline earth metals having large ionic radii are present in a larger quantity in the vicinity of the surface of the substrate, beat accumulation property at the surface of the substrate is superior to that in a deep part of the enamel layer, so that a thermal head can be obtained which has excellent thermal efficiency and response characteristics of temperature rise and fall. |
