Patent ID: 7718909

Claim:
A contact holding sheet comprising: a substrate mounting fixed contacts thereon; a holding sheet disposed in opposed relation with said substrate, said holding sheet having a first side facing said substrate and including a pressure-sensitive adhesive surface and a second side facing away from said first side, said holding sheet defining therein a plurality of holes; a plurality of dome-shaped movable contacts attached to said adhesive surface of said first side of said holding sheet in facing and opposed relation with said fixed contacts of said substrate, each said movable contact including a protrusion disposed at a central position on said movable contact and extending into a corresponding one of said holes of said holding sheet, the protrusion being the sole protrusion formed on the corresponding said movable contact; and a light guide film integrated with said holding sheet and positioned adjacent said second side of said holding sheet, said light guide film being disposed in adhering contact with respective upper portions of each of said protrusions.