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.

Abstract: Disclosed is a thermal head comprising: plural heating elements, and a driving circuit element comprising plural switching elements connected individually to the heating elements, gate elements connected individually to the switching elements, and a shift register connected to the gate elements; wherein the plural heating elements are divided into plural blocks, and the gate elements of each block are connected to plural shift registers in the same number of bits as the number of heating elements of each block individually; strobe signals in the same number as the number of divisions of the block are fed into gate elements corresponding to each block; a clock gate element is provided in each block in order to obstruct clock input into the shift register corresponding to each block when printing of each block is active; and each block is further divided into plural small blocks, and the heating elements corresponding to each small block are disposed in every different block.

Abstract: When the rear side of a heat resistant substrate having heating elements formed on the front side and a cooling board are adhered with an adhesive, the heat is accumulated in the substrate. To prevent this, the portions corresponding to the heating elements on the rear side are not adhered, but are protected with cooling compound, or adhesives are applied to both sides of the cooling compound, as it is known in prior parts, but they may cause uneven heat release from the substrate to the cooling board, or sacrifice the tacky action due to wetting of the adhesive with the cooling compound. In this invention, cooling compound or cooling adhesive is spread on the rear surface corresponding to the heating elements on the substrate, and an adhesive is applied to the parts separate from that area with grooves, thereby affixing the substrate and cooling member.

Abstract: The invention provide a thermal head wherein a head substrate composed by disposing plural heating resistance elements on a support board, and a flexible wiring substrate for connecting the heating resistance elements and an external circuit are adhered together by using a soft adhesive with the shear adhesion strength of 25 kg/cm.sup.2 or less.

Abstract: To the common electrode of the thermal head, the power source for heating and driving is connected to one end or both ends in the longitudinal direction of the common electrode. In this common electrode, as going from the connecting position of the power source for heating and driving, a voltage drop occurs, and the heat generation by the heating elements commonly connected to the common electrodes becomes uneven. Such uneven heat generation may lead to uneven contrast or defective coloring in the thermosensitive printing. The invention employs a conductive member which extends nearly over the entire length of the common electrode, and contacts with the common electrode over the entire length or at plural positions. As such conductive member, a metal foil or the like is used, and by inhibiting the occurrence of voltage drop, thermosensitive printing of high quality is realized.

Abstract: The face pressure distribution shape of the graze portion of the thermal head is made to be consistent with the temperature distribution shape of the graze portion of the thermal head. The temperature distribution shape of the graze portion of the thermal head is made to be consistent with the face pressure distribution shape of the graze portion of the thermal head. The graze portion of the thermal head is formed projectingly in two steps, and the heating resistor element of the thermal head is provided on the top portion of the graze portion of the thermal head. A thermal transfer printer having no ink void and no ink transfer unevenness can be obtained.

Abstract: A thin film type thermal head includes a head substrate member, a partial projected glaze portion mounted on the head substrate member, a plurality of heating resistor elements provided on the partial projected glaze portion with each of the heating resistor elements having a uniform thin thickness and two electrode end portions. A common electrode is provided on the partial projected glaze portion and an individual control electrode is also provided on the partial projected glaze portion.

Abstract: Disclosed is a thermal head in which a plurality of heat-generating elements are arranged on a substrate on a line oblique to the scanning direction of the thermal head so that the projecting scanning region of each heat-generating element overlaps the projection scanning region of the adjacent heat-generating element over a minute space without any blank clearance between the projecting scanning regions. In this thermal head, mutual thermal influences in the heat-generating elements can be completely eliminated, and the printing quality can be improved.

Abstract: In a thermal head comprising a plurality of heat-generating elements formed on a glaze layer on a substrate, grooves extending to the midway of the glaze layer in the thickness direction of the glaze layer and having a depth of 0.3 to 30 .mu.m are formed in the surface portion of the glaze layer between every two adjacent heat-generating elements. This thermal head is improved in both the rising and falling response characteristics of the heat-generating temperature by the presence of these grooves, and sharp images having a high resolving power can be obtained.