Abstract: In a thermal head consisting of one or more substrates, each of the substrates comprises a heating element, common electrodes arranged on one of the sides of the heating element, and individual electrodes arranged on the other side of the heating element. In the vicinity of the side edges of the substrate, the patterns of the two types of electrodes extend from the heating element toward the upper edge and lower edge of the substrate corresponding to the top side and bottom side of the trapezoid, respectively, in such a manner as to be directed at an angle toward the central portion of the substrate. This enables a plurality of substrates to be manufactured with the same electrode patterns, and all the substrates to have the same data transfer direction to simplify the wiring.

Abstract: A pair of holes are formed with a predetermined space therebetween on a long and narrow base plate. An adhesive is applied to the surface of the base plate. Head substrates each having a row of thermal resistors on the surface thereof are placed on the adhesive on the base plate such that the joint of the head substrates is positioned between the pair of holes of the base plate. The adhesive is hardened in the state in which the head substrates are pushed upward by a thruster(s) means inserted into a pair of holes while the base plate is supported from below and the head substrates is pressed from above. The base plate is bonded to a radiating plate by an adhesive only at the central portion. Thus, there is no difference in level at the joint of the head substrates, and even when the radiating plate expands due to heat, the base plate is not deformed.

Abstract: A heater comprises an insulating substrate which carries a parallel pair of conductor strips. The respective conductor strips are spaced from each other transversely thereof but electrically connected to each other by a plurality of heating resistors which are spaced longitudinally of the respective conductor strips. Advantageously, the heating resistors are arranged or configured so that the heater will have a temperature distribution which is equalized longitudinally.

Abstract: A divisional-type thermal printhead comprises an insulating base board, and a plurality of unit substrates arranged in series on the base board. The unit substrates have their respective common electrodes in electrical independence of each other. Further, the base board is formed with a plurality of conductor films extending under the respective unit substrates in corresponding relation thereto, and each of the conductor films is electrically independent of the other conductor films but electrically connected to the common electrode of a corresponding unit substrate.

Abstract: A heater for a sheet material comprises an insulating substrate, and a plurality of heating resistor strips formed on the substrate to extend in parallel to each other between first and second common electrodes. At least one of the resistor strips is electrically connected to both of the first and second common electrodes while at least another of the resistor strips is electrically separated from the first common electrode.

Abstract: A heater for a sheet material comprises an insulating substrate and a main resistor strip formed on the substrate. The substrate is further formed with auxiliary resistor strips adjacent to both ends of the main resistor strip. In operation, the main and auxiliary resistor strips are actuated simultaneously for heat generation. As a result, the additional heat generated by the auxiliary resistor strips compensates for higher heat dissipation at both ends of the heater, thereby equalizing the temperature distribution longitudinally of the heater.

Abstract: A heater for heating a moving sheet material by contact therewith is used, for example, in electrophotographic apparatus for fixing toner to printing paper. The heater comprises an insulating substrate formed with a striplike heating element on its upper surface, and a support plate for supporting the substrate. A higher heat preserving property is given to the opposite end portions of the heating element than to a longitudinal intermediate portion thereof to thereby compensate for a temperature reduction at the element end portions and make the heating element uniform in temperature over the entire length thereof.

Abstract: A heater comprises an insulating substrate which carries a pair of transversely conductor strips, a resistor line extending between the respective conductor strips. The respective conductor strips are connected to the resistor line by electrode teeth spaced longitudinally of the main resistor line and arranged in staggered relation on both sides of the resistor line.

Abstract: A pair of holes are formed with a predetermined space therebetween on a long and narrow base plate. An adhesive is applied to the surface of the base plate. Head substrates each having a row of thermal resistors on the surface thereof are placed on the adhesive on the base plate such that the joint of the head substrates is positioned between the pair of holes of the base plate. The adhesive is hardened in the state in which the head substrates are pushed upward by thrusting means inserted into a pair of holes while the base plate is supported from below and the head substrates is pressed from above. The base plate is bonded to a radiating plate by an adhesive only at the central portion. Thus, there is no difference in level at the joint of the head substrates, and even when the radiating plate expands due to heat, the base plate is not deformed.

Abstract: A line-type thermal printing head comprises an elongate support plate, an elongate head substrate mounted on the support plate, and a strip-like auxiliary substrate mounted on the support plate to extend longitudinally of the head substrate. The head substrate is formed with a heating resistor line extending longitudinally of the head substrate, and a common electrode extending substantially in parallel to the resistor line adjacent to a longitudinal edge of the head substrate. The auxiliary substrate has a side surface which is substantially perpendicular to the head substrate and formed with a longitudinal conductor strip connected electrically to the common electrode through a conductive member.

Abstract: A method is provided for making unit heads from a material head. The unit heads are used to constitute a divisional-type thermal head. The material head includes an elongate insulating substrate carrying a longitudinal array of heating dot portions, and a protective layer extending longitudinally of the material head to cover the array of heat dot portions. According to the method, the material head is cut along at least one cutting line which extends transversely of the material head at a position between two adjacent heating dot portions, wherein the protective layer has cutouts which extend from the respective longitudinal edges of the protective layer toward the array of heating dot portions at the position of the cutting line.