Patent ID: 8835785

Claim:
A key switch structure comprising: a key top; a linking mechanism adapted to support and allow elevation of the key top; a membrane sheet having a contact point portion; a back plate disposed below the membrane sheet and supporting the linking mechanism, the back plate including a through-hole; a light emitting element disposed adjacent to the back plate and outside of a region of the back plate that the key to covers; a sheet member having the light emitting element disposed thereon; and a holder member disposed on the membrane sheet and supporting the linking mechanism, the holder member including a protrusion portion that protrudes from a part of the holder member toward the back plate, the protrusion portion being both fitted and inserted into the through-hole, and a tip portion of the protrusion portion is fixed to the back plate, wherein the back plate has a light guiding function that guides light emitted by the light emitting element, that is disposed outside of the region of the back plate that the key top covers, to the region of the back plate that the key top covers, wherein a base portion of the protrusion portion is provide with a flange portion having a diameter larger than that of the through-hole, and wherein a thickness of the flange portion is thicker that that of the membrane sheet, wherein the membrane sheet includes a hole into which the flange portion is fitted, the diameter of the flange portion is smaller than that of the hole of the membrane sheet.