Abstract: A key sheet provided with a plurality of buttons formed thereon, a metal dome sheet, and a printed board are incorporated in a stacked state into a lower body provided with an upper case and a lower case. A plurality of protrusions for internally supporting the upper case are provided on the key sheet. By virtue of the above construction, even when external pressure is applied to the upper case, the upper case is supported by the plurality of protrusions to prevent the upper case from being deformed or curved, and buttons can be prevented from being pushed by the upper case. Therefore, a portable communication unit can be realized which can reduce size and weight without increasing the number of components and can protect the body and electronic components, for example, against impact and external pressure.

Abstract: There is provided a cellular phone housing formed with a base made of a resin material by molding, wherein the base is coated with a metal multilayer including a lower metal layer formed on a surface of the base with metal plating and an upper metal layer formed on the lower metal layer with metal plating, and wherein the lower metal layer is made of a first metal which is ductile and the upper metal layer is made of a second metal which is brittle compared with that of the first metal.

Abstract: A portable communication device has a plurality of projections formed on one or both of an upper casing and a lower casing; a plurality of through holes formed on at least a printed circuit board, on which various types of electronic parts are mounted, housed in a housing so to allow the projections to pierce through them; and the projections designed to pierce through the through holes of the printed circuit board to fix the printed circuit board between the upper casing and the lower casing.

Abstract: A key sheet provided with a plurality of buttons formed thereon, a metal dome sheet, and a printed board are incorporated in a stacked state into a lower body provided with an upper case and a lower case. A plurality of protrusions for internally supporting the upper case are provided on the key sheet. By virtue of the above construction, even when external pressure is applied to the upper case, the upper case is supported by the plurality of protrusions to prevent the upper case from being deformed or curved, and buttons can be prevented from being pushed by the upper case. Therefore, a portable communication unit can be realized which can reduce size and weight without increasing the number of components and can protect the body and electronic components, for example, against impact and external pressure.

Abstract: There is provided a cellular phone housing formed with a base made of a resin material by molding, wherein the base is coated with a metal multiplayer including a lower metal layer formed on a surface of the base with metal plating and an upper metal layer formed on the lower metal layer with metal plating, and wherein the lower metal layer is made of a first metal which is ductile and the upper metal layer is made of a second metal which is brittle compared with that of the first metal.

Abstract: An elastic modulus of an element of a material including fibers in a selected direction is determined as follows. First, a parallel elastic modulus, an orthogonal elastic modulus and fiber orientation of the material are stored. The elastic modulus of the element is determined based on the first elastic modulus, the second elastic modulus and an angle between the fiber orientation of the element and the selected direction such that the elastic modulus is determined as a function of the angle between the fiber orientation of the element and the selected direction when the selected direction is neither parallel nor orthogonal to the fiber orientation of the element.