The light guide film in the LGF membrane switch guides the light from the LED to the interface, enabling the user to view the printed icons. This technology is of great value as part of a membrane switch because it can be used in a variety of lighting conditions.

Backlighting can be one of most valuable and positive attributes when a more intuitive user experience need to provided for your end users. There are four standard methods for back lighting LGF membrane switch.

LEDS are mounted as indicator lights. LEDS can either be surface-mounted to the circuit layer or be placed on a separate LED layer.Electroluminescent panel(EL) is used for conducting uniform surface illumination of complex shapes. The operation life is 30008000 hours, and it depends on quality of phosphors which need to be driven by AC adapter.

Light Guild Film/Plate( LGF/LGP), using top/side fire LEDS to light entire keycap text and various icons on a panel to make the lighting more intuitive

Besides backlighting,the reflective way of lighting can be used to enhance products experience Luminescent ink is printed on the graphic layer,primarily button area;Metallic ink such as silver mirror ink is printed on graphic layyer Electroplated coating on whole Pet layer is deplated