Abstract: A thermal printhead includes a ceramic substrate, a resistor layer that defines a plurality of heat-generating portions arranged in the main scanning direction, a common electrode connected to the plurality of heat-generating portions, a plurality of individual electrodes arranged in the main scanning direction, which respectively extend in the sub-scanning direction, which are electrically connected to the common electrode via the heat-generating portions, and which have pads disposed on the respective end portions thereof, a glaze layer, a protective layer covering the resistor layer, the common electrode, and the plurality of individual electrodes, a drive IC, and a plurality of wires. The protective layer has a shape that exposes the plurality of pads, and covers a band region located between the drive IC and the plurality of pads. Thus, the thermal printhead avoids any interference with a platen roller while achieving a reduction in size.

Abstract: A thermal printhead (1) comprises a substrate (2), an electrode pattern (3) formed on the substrate, including a common electrode and a plurality of individual electrodes, a heating resister (5)connected to the electrode pattern (3), and a protective coating (8) including a plurality of layers (81, 82, 83, 84) covering the electrode pattern (3) and the heating resister (5). The protective coating includes an outermost layer (84) composed mainly of SiC and an admixture of carbon.

Abstract: The thermal printhead (1) includes an insulating substrate (2), a heating resister (5) formed on the substrate (2), a first glass coat layer (7) formed on the substrate (2) for covering the heating resister (5), and a second glass coat layer (8) formed on the first glass coat layer (7). The heating resister (5) has a centerline average roughness not greater than 0.3 &mgr;m. The first glass coat layer (7) has a centerline average roughness not greater than 0.1 &mgr;m.

Abstract: A thermal printhead includes a head substrate (1), a heating resistor (5) provided on the head substrate, a plurality of individual electrodes (2) connected to the heating resistor, and a common electrode (3) connected to the heating resistor. The thermal printhead is further provided with a first coating layer (6) covering the heating resistor, the individual electrodes and the common electrode, and a second coating layer (7) which is formed on the first coating layer and made of sialon containing a conductive material as an additive. The first coating layer is formed with at least one through-hole (6a) or notch (6a′), so that the second coating layer is electrically connected to the common electrode via the through-hole or the notch.

Abstract: A thick-film thermal printhead includes an insulating substrate, an electrode pattern formed on the substrate and a linear heating resistor electrically connected to electrode pattern. The electrode pattern includes a common electrode and a plurality of individual electrodes. The common electrode includes a plurality of comb-teeth and a main conductor connected to the comb-teeth. The distance between the main conductor and the heating resistor is 0.25-0.75 times the width of the heating resistor.

Abstract: A thermal printhead (A) includes an insulating substrate (10) having an upper surface (10a) and a side surface (10b), and a heat retaining glaze layer (11) formed on the substrate (10). A heating resistor (13) is formed on the glaze layer (11). The thermal printhead (A) further includes a common electrode (12) and a plurality of individual electrodes. The common electrode (12) has a plurality of teeth (12a) connected to the heating resistor (13), and a connecting portion (12b) which connects the teeth (12a) with each other. An electrode auxiliary layer (14) is formed on the connecting portion (12b). The heating resistor (13) and the electrode auxiliary layer (14) are covered with an overcoat layer (16) which is, in turn, covered with a protective layer (17). The connecting portion (12b) of the common electrode (12) directly contacts both the glaze layer (11) and the upper surface (10a) of the substrate.

Abstract: A thermal printhead 1 according to the present invention includes a multiplicity of heating elements 4a formed in a row on an obverse surface of an elongated substrate 2 at a portion which is offset widthwise toward one longitudinal side of the substrate, and a protective film 8 formed on the obverse surface of the substrate 2 at the widthwise offset portion for covering the heating elements 4a. The protective film 8 is formed to extend on the obverse surface of the substrate 2 continuously from the widthwise offset portion onto one longitudinal side surface 2a of the substrate. A longitudinal edge 8b of the protective film 8 directed toward the other longitudinal side of the substrate 2 is tapered.