US Patent 8168903 Illuminated keyboard

An illuminated keyboard includes a frame plate, a character keycap, a light source, a membrane plate, a switch circuit plate and a base plate. The character keycap is connected with the frame plate, and movable upwardly or downwardly with respect to the frame plate. The light source is disposed under the character keycap for emitting invisible light. The character keycap, the frame plate, the membrane plate, the switch circuit plate and the base plate are sequentially arranged from top to bottom. The illuminated keyboard further includes a luminous substance, which is excited by the light source to generate visible light to irradiate the illuminated keyboard.