Abstract: A method of inspecting a crack in a ceramic substrate that is not exposed on the surface. The method can detect all cracks and make objective judgement possible by expressing the inspection result as numerical data. Conductors are disposed on both faces of a ceramic substrate, wherein one of the conductors is a conductive liquid; the insulation resistance value or an electric property dependent on the insulation resistance is measured with the conductive liquid or other conductors electrically connected to the conductive liquid which are used as electrodes.

Abstract: A plate assembly for ink-jet-type printing head assures a smooth ink flow and prohibits fluctuation in ink discharge quantity and speed to realize a satisfactory printing quality. A plurality of plates are bonded each other by using a thermoplastic-resin intermediate sheet having a shape corresponding to the opposite surfaces of adjacent plates. The intermediate sheet has ink passage openings of a dimension which includes a reference contour which is an axial projection of a corresponding opening in the plate. The ink passage opening in the intermediate sheet has a periphery which is set-back from the reference contour by a predetermined amount in the reference direction connecting adjacent ink passage openings, and by an increased amount in other directions. The plates and the intermediate sheet are superimposed one above the other and subsequently heated under pressure to form an integral plate assembly.

Abstract: A process for forming a film on a ceramic substrate or on a fired film formed thereon includes coating, on a ceramic substrate or on a fired film formed thereon, a material which becomes a metallic film or a ceramic film upon firing, to form an as-coated film, irradiating the as-coated film with an energy beam which does not damage the ceramic substrate or the fired film formed thereon to such an extent that it becomes useless and which can decompose and remove the as-coated film, to trim the unrequired portion(s) of the as-coated film, and firing the trimmed as-coated film to form a desired film. The film can be formed on a ceramic substrate or on a fired film formed thereon while the damage to the substrate or the fired film is minimized.

Abstract: A method of brazing a plurality of components by heating the components superposed on each other with a brazing material interposed between adjacent bonding surfaces of the components, wherein the brazing material has a relatively low degree of wettability with respect to the material of the components to be brazed, and is applied to a patterned film of a high-wettability metal having a relatively high degree of wettability with respect to the brazing material, which film is formed on at least one of bonding surfaces of the components, so as to cover predetermined areas of the bonding surface while leaving adjacent non-bonding areas of the bonding surface uncovered so as to restrict the flow of brazing material.

Abstract: A recording head having an electrically insulating substrate (11), at least one recording electrode (12) formed on one of opposite major surfaces of the substrate, and at least one return circuit electrode (13) formed on the other major surface. The substrate is formed of a material whose wear resistance is lower than that of the electrodes, and includes a proximal portion, and a thin-walled distal end portion (16) extending from the proximal portion for contact with an electrically resistive layer of a recording medium or an ink ribbon. The distal end portion has a constant thickness smaller than that of the proximal portion, and the substrate has a recessed portion formed in at least one of the opposite major surfaces such that the recessed portion at least partially defines the thickness of the distal end portion. A reinforcing layer (17) is disposed to reinforce the thin-walled distal end portion, such that at least a portion of the reinforcing layer is positioned in said recessed portion.

Abstract: A recording head including at least one electrode, and a substrate structure for supporting each electrode. Each electrode and the substrate are held in contact with a recording medium or a planar intermediate member interposed between the recording medium and the recording head, so that an electric current is applied to the recording medium or the intermediate member. The substrate has a distal end portion extending from a proximal portion for contact with the recording medium and the intermediate member. The distal end portion has a constant thickness smaller than that of the proximal portion, as viewed in a direction perpendicular to a direction of extension of the end portion. The distal end portion is made of a material whose wear resistance is lower than that of the electrode.

Abstract: A recording head operable to apply an electric current, having at least a plurality of recording electrodes and at least one return circuit electrode, which are held in contact with a sheet having at least an electrically resistive layer which generates heat upon energization thereof through the recording and return circuit electrodes. The recording head has an insulating layer including an electrically insulating material and at least one metallic sheet positioned in the electrically insulating material. This insulating layer is disposed between an array of the plurality of recording electrodes and the return circuit electrode or electrodes, so as to form a multi-layer structure which includes the recording electrodes, return circuit electrodes(s) and insulating layer. The recording and return circuit electrodes are formed of an electrically conductive material which has a higher degree of water resistance than that of the insulating layer.