An electroluminescent lamp (EL) is a thin-layered, electric system, usually a foil, that emits light with its entire surface under the influence of an applied voltage. EL lamps are used in various branches of the electronics industry, especially in liquid-crystal displays (LCD).
EL lamps are widely used in the membrane keyboards manufactured by our company. As they are integrated into the keyboard, a complete air-tightness of the system is preserved.




Lamp brightness (lifetime)
studies conducted by Du Pont in 1999


The illumination occurs when alternating voltages between 60 – 150 V and frequencies between 50 – 1000 Hz are applied. The usual voltage and frequency used in EL lamps are 130 V and 400 Hz. At these parameters, the average life expectancy of an EL lamp is ca. 5000 h after which the lamp brightness is believed to fall by 50%. If the value of either voltage or frequency is reduced, the current strength that is passed through the lamp decreases, and life expectancy of a lamp increases.
The colour of the illumination of an EL lamp depends on the type of ink used. It can be white, blue-green and yellow-green. Filters applied on the lamp surface can to some extent modify the shade of the illumination.



EL lamp brightness (voltage 115V, 400Hz)
studies conducted by Du Pont in 1999