Abstract: A lighted switch device, comprising a substrate, a switch provided on a first surface of the substrate, a light source provided on a second surface of the substrate, a key top to press the switch, and a light guide mechanism to guide light emitted from the light source to the key top or a periphery of the key top, the light guide mechanism including a first light guiding member to hold the key top and a second light guiding member disposed to surround the light source, the light emitted from the light source being guided through the second light guiding member to the first light guiding member holding the key top.

Abstract: A lighted switch device, comprising a substrate, a switch provided on a first surface of the substrate, a light source provided on a second surface of the substrate, a key top to press the switch, and a light guide mechanism to guide light emitted from the light source to the key top or a periphery of the key top, the light guide mechanism including a first light guiding member to hold the key top and a second light guiding member disposed to surround the light source, the light emitted from the light source being guided through the second light guiding member to the first light guiding member holding the key top.

Abstract: A method for manufacturing polyurethane foam by mixing (a) polyisocyanate, (b) polyol, (c) blowing agent, (d) catalyst and, as required (e) surface active agent, filler, or other such additive, the said method being characterized in that the polyisocyanate (a) is a prepolymer with isocyanate end groups produced from a polyester polyol and a blended polyisocyanate component comprising 45-95 weight % of diphenylmethane diisocyanate and 55-5 weight % of a polymethylene polyphenyl polyisocyanate with a functionality of 3 or more.