US Patent 9170008 Disk having an illuminated switch surface

A disk having an illuminated switch surface is described. The disk has a transparent substrate, an electrically conductive structure, which forms a switch surface, a flat conductor, which is electrically connected to the electrically conductive structure by means of an electrical connecting element, a light-irradiation means, which has at least one light source and is arranged on the flat conductor and on a lateral edge of the substrate. Light is coupled into the disk from the lateral edge of the substrate and from a light-refracting means, which is arranged in the region of the disk irradiated by the light of the light-irradiation means.