US Patent 7841791 Keyboard, lighting module for keyboard and electronic apparatus

According to one embodiment, a keyboard includes keytops supported on a substrate and a membrane switch placed between the keytops and the substrate. The membrane switch has an electrically insulating membrane sheet on which a plurality of contacts operated by the keytops are formed. A light source is mounted on the membrane sheet. A conductor pattern configured to supply an electric current to the light source is formed on the membrane sheet. Further, a lightguide plate configured to lead light emitted by the light source to the keytops is stacked on the membrane sheet.