Thermal head

Abstract

A thermal head comprising a resistance heating element and electrodes for feeding electric power to the resistance heating element formed on an insulating substrate, and a protective layer of filler-containing-glass formed so as to cover the resistance heating element and electrodes, wherein the specific gravity of the glass for forming the protective layer is equal to or higher than the specific gravity of the filler. In this manner, while maintaining the smoothness and enhancing the ear resistance of the protective layer surface, the thermal expansion coefficient of the protective layer is decrease to reduce the thermal stress due to pulse heat generation from the resistance heating element, and moreover the thermal conductivity of the protective layer is enhanced, so that a favorable recorded image is obtained for a long period.

Dependencies are inferred from the claim text.