present invention relates to portable electronic devices, and more specifically to supplemental keyboard lighting for a portable electronic device.
A laptop or “notebook” portable computer serves as an example of a portable electronic device.
A portable device such as computer 100 is intended to be used in many different environments. For example, computer 100 may be used out of doors, in a car, on an airplane, or in nearly anywhere else the user desires. Computer 100 may operate for a limited time on battery power when no external supply of power is available. Not all of these usage locations are ideal working environments. For example, during a long airline flight, cabin lighting is often extinguished so that the passengers can sleep. A passenger wishing to continue working at his seat after “lights out” may have difficulty seeing keyboard 103.
Various devices have been proposed for illuminating a portable device keyboard. Many require additional equipment to be carried with the portable device. Kim (U.S. Pat. No. 6,336,727) describes a lighting device integrated into a cursor control device that resides near the center of a computer keyboard. However, not all computers or other portable devices use the kind of cursor control device described by Kim, and such a device may not extend high enough above the keyboard to provide sufficient light.
A designer of skill in the art may choose the number, orientations and surface treatments of the various surfaces of keyboard light 205 so as to work effectively to achieve a design goal using the light source chosen in a particular embodiment. For example, the designer may strive to distribute the light from the chosen light source as evenly as possible over keyboard 203, or may strive to deliver the largest possible portion of the light from the light source to keyboard 203. Other design goals may be envisioned.
Preferably, keyboard light 205 is rotatable about its vertical axis 305, so that light may be directed preferentially to particular parts of keyboard 203.
During times when supplemental illumination is not needed or desired, moving member 306 may be retracted into base portion 201.
The retraction of keyboard light 205 and its extension to its operating position are preferably performed using a “push-push” mechanism. A push-push mechanism allows alternately latching of a surface in a retracted and an extended position. Each transition between the retracted position and the extended position is accomplished by pushing on the mechanism. That is, the push-push mechanism alternately places moving member 306 in its operating position and its retracted position. In example computer 200, the user presses on the upper surface 304 (shown in
In a preferred embodiment, keyboard light 205 comprises an illuminated pushbutton switch, which further comprises a push-push mechanism, so that LED 301 is illuminated automatically when moving member 306 is in its operating position and is shut off automatically when moving member 306 is in its retracted position. Alternatively, control of LED 301 is independent of the position of moving member 306. For example, LED 301 may be controlled by a separate switch actuated by the user of computer 200, or may be controlled through software installed in computer 200.
Push-push mechanisms and illuminated pushbutton switches are well-known in the mechanical arts and need not be described in detail here. See, for example, U.S. Pat. No. 3,651,700 to Bailey, which describes an example push-push mechanism. U.S. Pat. No. 3,969,609 to Wanner et al. describes an example illuminated push button switch that may be illuminated in response to its selected position, or may be illuminated by a control independent of the switch position. Illuminated pushbutton switches are available from a variety of manufacturers, including NKK Switches of Scottsdale, Ariz., USA and ITT Industries, Cannon of Newton, Mass., USA.
While a laptop portable computer has thus far been used as an example portable electronic device in which the invention may be embodied, the invention may be embodied in other portable electronic devices as well, for example a personal digital assistant (PDA). A PDA is typically a handheld device that comprises a display screen and a keyboard. Software and hardware comprised in a PDA may enable the device to act as a wireless telephone, an internet access device, or to perform computer-like functions for the convenience of the user. For example, a PDA may allow the user to access electronic mail, store and play digital sound files, store and display digital photographs, to do word processing, or other functions.