US Patent 7582839 Backlighted key for a keypad of an electronic device

The invention relates to a key plunger for a key of an electronic device. The plunger comprises: a stalk made of a transparent material allowing light to pass through; a plinth connected to the top of the stalk; and a body section connected to the top of the plinth made of a translucent, light-diffusing material. The body section is shaped to fit snugly within an interior of a cap for the key. The plunger is made from a two-shot moulding process for forming the stalk and the section. The plunger may be part of a key assembly that also has a key cap shaped to snugly fit over the plunger and a backlight to light an interior of the cap.