Abstract: A contact holding sheet with a light guide without using a holding sheet with protrusions made of resin is provided. The contact holding sheet does not require a protrusion fabrication process, thereby reducing costs, and making the contact holding sheet thin without forming the protrusions on the holding sheet. The contact holding sheet includes a holding sheet opposed to a substrate, fixed contacts provided on the substrate, and dome-shaped movable contacts attached to a pressure sensitive adhesive surface of the holding sheet. The dome-shaped movable contacts face the substrate, and the movable contacts are opposed to the fixed contacts of the substrate. The protrusions are formed at central positions of the movable contacts and positioned inside holes formed in the holding sheet. The holding sheet and a light guide film are integrated with adhesion in a state where the light guide film is laid on upper portions of the protrusions.

Abstract: There is provided a contact spring in a small-sized push-button switch capable of lessening contact obstacle between contacts caused by fine dust, and reducing variation in load characteristics even if heat is applied thereto or the switch is repetitively operated.

Abstract: There is provided a switch which is excellent in stability in electric contact between an edge part of a contact spring and a fixed contact part, ensures a stroke required for an eccentric load which is imposed on the contact spring and reduces variations in clicking feeling without shortening a life of the dome-shaped contact spring which can be clicked. A depression is formed on an inner central part of the contact spring, namely, on a movable contact part and the edge part formed on the periphery of the depression is allowed to contact the surface of the fixed contact part by a line contact, thereby ensuring electric stability of contact between the edge part and the fixed contact part. Since the movable contact part has no hole, no dust enters the switch, thereby preventing a life of the contact spring from being shortened.

Abstract: A compact, thin switch of a simple contact structure to be operated for switching operations by an external pressure comprises a base, four stationary contacts arranged on the base and isolated from each other, a curved, self-resetting first movable contact plate formed of a conductive spring material, and mounted on the base, and a curved, second movable contact plate formed of a conductive spring material, and put on top of the first movable contact plate.