Abstract: A developing roller comprising an electroconductive substrate and an electroconductive elastic layer constituted by a single layer on an outer periphery of the substrate. The elastic layer contains a diene-based rubber, has a thickness of 0.30 mm or more, and the elastic layer has a crown shape in which an outer diameter of a center portion in a longitudinal direction along an axis of the substrate is larger than an outer diameter of each of both end portions in the longitudinal direction. Elastic moduli E11, E12 and E13 in a first region of the elastic layer in cross-sections at positions P1, P2 and P3 of the elastic layer are each 500 MPa or more.

Abstract: A semiconductor device includes a source electrode and a drain electrode formed on an active region of the semiconductor layer, a gate electrode formed on the active region of the semiconductor layer, a first insulating film formed on the semiconductor layer and covering the gate electrode, the first insulating film having a step portion following a shape of the gate electrode, a first field plate formed on the insulating film and located between the gate electrode and the drain electrode and separated from the step portion, a second insulating film formed on the first insulating film to cover the step portion and the first field plate, and a shield electrode formed on the second insulating film, the shield electrode extending from a portion located above the first field plate and a portion located above the gate electrode.

Abstract: A semiconductor device includes a source electrode and a drain electrode formed on an active region of the semiconductor layer, a gate electrode formed on the active region of the semiconductor layer, a first insulating film formed on the semiconductor layer and covering the gate electrode, the first insulating film having a step portion following a shape of the gate electrode, a first field plate formed on the insulating film and located between the gate electrode and the drain electrode and separated from the step portion, a second insulating film formed on the first insulating film to cover the step portion and the first field plate, and a shield electrode formed on the second insulating film, the shield electrode extending from a portion located above the first field plate and a portion located above the gate electrode.

Abstract: A cloth cutting knife 16 is structured such that the length of the cutting edge thereof is set shorter than the length of the side sewing portions of a buttonhole to be formed, and a buttonhole having a length corresponding to the length of the right and left side sewing portions can be formed by moving up and down the cloth cutting knife 16 two or more times. The cloth cutting knife 16 is moved up and down at least once during formation of the stitches of the right and left side sewing portions. Also, the cloth cutting knife 16 is moved up and down once each time a given number of stitches of the right and left side sewing portions are formed. The given number of stitches is set in accordance with both of the length of the cutting edge of the cloth cutting knife 16 and the length of the buttonhole to be formed.

Abstract: A buttonhole sewing machine includes a holding mechanism attached to a holder arm which reciprocates in a direction perpendicular to an amplitude direction of a needle. The holding mechanism includes a workpiece holder plate and constitutes a parallelogram linkage. The holding mechanism maintains a parallelogram shape even when the holder plate slants on a fold of the workpiece, and securely holds the workpiece. This buttonhole sewing machine also includes a cutting mechanism which cuts thread and braid in a short manner even when the holder plate slants. The cutting mechanism has a rotary cutter and a fixed cutter, and the fixed cutter is fixed on the holder plate while inclined from a proximal portion to a distal portion. A wire member is connected to the mobile cutter to facilitate the rotation of the rotary cutter even when the holder plate slants.

Abstract: An electrode structure of an electrode of a refractory metal or a silicide thereof on a layer of In.sub.x Ga.sub.1-x As (0<x<1) on a substrate of a III-V compound semiconductor is ohmic and is stable even at a high temperature, for example, 900.degree. C. This high temperature stable ohmic electrode structure allows ion implantation into the substrate with the electrode as a mask followed by annealing to form a doped region in alignment with the edge of the electrode.