Computer keyboard backlighting
Embodiments of a peripheral backlighting system for keyboards are shown and described, which include one or more light-emitting panels exterior to the keyswitches of the keyboard. The panels are preferably electroluminescent material or light-emitting chemical cells and surround at least two sides, and preferably all sides, of the actuation portion of a keyswitch or the space in which the actuation portion slides up and down during use. Alternatively, the panel(s) may extend substantially continuously between and underneath a plurality of keyswitches. The panels extend closely adjacent to the actuation portion or actuation path, or under the keyswitch, to be as far under the key cap as possible without extending into the keyswitch. Preferably, the keyswitch is translucent or partially translucent, and the housing plate over the light-radiant panels, if any, is at least partially translucent or transparent. This way, the light from the light-emitting panels radiates upward through, and preferably around the outer surface of, the translucent keycaps, rather than up through an aperture or lightpipe in the center of the keycaps.
1. A backlit computer keyboard comprising:
a keyboard housing;
a circuit board or membrane;
a plurality of keyswitches operatively connected to said housing, each keyswitch having a cap portion for being forced downward by a user and having a translucent or transparent portion, and an actuation portion between the cap portion and the circuit board or membrane for transmitting force to the circuit board to effect switching of the circuit board or membrane;
a substantially planar panel of light-emitting material above said housing and above said circuit board or membrane, wherein the panel of light-emitting material extends between and underneath said cap portions and is the uppermost generally horizontal panel of the keyboard beneath the cap portions;
wherein said panel emits light directly up through said keyswitches by passing through said translucent or transparent portion of each cap portion; and
the keyboard further comprising gaps between said cap portions, and wherein the cap portions each have an outer perimeter and wherein said panel comprises non-light-emitting areas directly below the gaps so that the panel radiates light from near the outer perimeters up through the gaps at an angle to said panel but so that the panel does not radiate light straight up from below the centers of the gaps.
2. A backlit keyboard as in claim 1 , wherein the panel of light-emitting material comprises a light-emitting electrochemical cell.
3. A backlit keyboard as in claim 1 , wherein the panel is an electroluminescent membrane.
4. A backlit keyboard as in claim 1 , further comprising a control device that automatically turns off the light emitted by said panel after a period of inactivity of the keyboard.