Backlighting methods for keyboards, such as screen-printed light guides or direct LED lighting, can be costly, thick, and power-intensive. Global Lighting Technologies (GLT), Inc., has introduced a thinner, LED-based backlight for use with desktop or notebook PC keyboards. Because the light that it produces is brighter and more uniform, the keyboards require fewer LEDs.
The backlight design extracts more light from the backlight through to the keyboard. This selectively illuminates only those areas where light is required, increasing the light output and brightness at the precise points where it is needed. The design uses side-firing LEDs that focus their light into a high-performance light guide.
Designers can, in some cases, make use of diversion features that are molded directly into the light guide to ‚â€œbend‚â€ a portion of the light around a potential thru-hole. LEDs can be located on the edge of the light guide or in the middle of the backlight, depending on the surrounding geometry. Typical backlight thicknesses for desktop keyboards are from 0.6 to 0.8 mm. For laptop keyboards, the range is even thinner – from 0.3 to 0.4 mm.
Global Lighting Technologies, Inc.
:: Design World ::
Filed Under: Semiconductor, Lights • signal lamps • indicators