Illuminated keyboard

An illuminated keyboard, comprising:

• a plurality of keys, each of the keys comprising:
• a key cap;
• and
• a movable connecting component, disposed below the key cap and connected to the key cap;
• a metal plate, disposed below the keys and bearing the keys, the metal plate comprising a plurality of metal domes, wherein each of the metal domes is protrudingly formed corresponding to one of the keys;
• a thin film circuit board, disposed below the metal plate, wherein the thin film circuit board comprises a plurality of electrical contact parts, the electrical contact parts are located on an upper surface of the thin film circuit board, and each of the electrical contact parts corresponds to one of the metal domes, so that when a user presses the key downward, the metal dome may move downward to get in contact with the corresponding electrical contact part to conduct the electrical contact part and generate a corresponding key signal;
• and
• a backlight module, disposed below the thin film circuit board, wherein the backlight module comprises a light guide plate, a reflecting plate, and a plurality of illuminating components, the illuminating components emit a plurality of light beams toward the light guide plate, and the light beams are refracted by the light guide plate or reflected by the reflecting plate to the key cap,
• wherein each of the electrical contact parts comprises an anode contact and a cathode contact, the anode contact is located at a central position of the electrical contact part, and the cathode contact is in a ring shape and encloses the anode contact, wherein when the metal dome is pressed downward, the metal dome gets in contact with the anode contact and the cathode contact at the same time, so as to conduct the anode contact and the cathode contact.