US Patent 9214301 Luminous keyboard device

A luminous keyboard device includes a keypad module, a supporting plate, a flexible circuit board, a light-emitting element, a reflective layer, and a light guide plate. The supporting plate includes plural receiving parts. The flexible circuit board is contacted with the plural receiving parts to form plural bent structures. The light-emitting element and the reflective layer are disposed on the flexible circuit board. When a light beam is emitted by the light-emitting element, the portion of the light beam that is not directed to the light guide plate is reflected back to the light guide plate by the reflective layer on the plural bent structures. Consequently, the amount of light introduced into the light guide plate increases.