| 摘要 |
<p>PURPOSE:To obtain a small-size and light-weight thermal head with high energy effi ciency which ensures superior printing quality even during high-speed printing, by a method wherein the thermal head consists of a substrate 10<-6>-10<2>OMEGA.cm in specific resistance and electrodes which are so formed thereon as to be opposed to each other. CONSTITUTION:With a substrate 1 of 10<-6>-10<2>OMEGA.cm specific resistance, for example, a glassy carbon is used after being shaped into a board having a given thickness. The current, when passed between electrodes 2 and 3, flows on the shortest route therebetween which is in the vicinity of the surface of the substrate 1, as shown by an arrow 4. As a result, the vicinity of the surface 5 disposed between the electrodes is heated to a large extent with a low voltage applied thereto. The substrate 1 has an extremely high heat efficiency per unit input-watt and decreases in heat conductivity as the temperature increase, thereby being enhanced in heat accumulation properties due to voltage application and in heat radiation properties due to voltage cut-off. The resulting heat flow shown by an arrow 6 provides the optimum action as a mate rial for a thermal head. By taking advantage of these properties, an independent substrate of carbon material can be used as a heating element, a substrate, and a heat radiation element.</p> |
