A white or amber
LED (depending on model) is located on the top edge of the
display, illuminating the keyboard to allow use in low-light conditions. It is activated with the key combination
Fn-PgUp (the bottom left and top right keys of the keyboard). Later ThinkPads use the combination
Fn-Space instead. Lenovo later started to include backlit keyboards, and some models included both the ThinkLight and a backlit keyboard. For those models, the
Fn-Space shortcut is also used in conjunction to control a backlit keyboard (if the laptop has it). The on-screen display of ThinkPad computers will display a light on and a light off indicator. The ThinkLight can be activated when the monitor is on or off but not while the computer is off. The G series and SL series omit the ThinkLight. A few ThinkPads (17" W700 and W701) have featured the ThinkLight with dual white LEDs. Early in the development of the ThinkPad X300, plans were made for a ultra-violet LED to be used and special ink that would allow them to glow in the dark, but this concept was removed from the final product. When the
25th anniversary edition of ThinkPad was in its concept phase, it was equipped with two ThinkLights. == Alternatives ==