Electroluminescent Lamp Backlighted User Interfaces
Electroluminescent backlighting on flat user interfaces with graphic overlays provides an even elimination when illuminated with electroluminescent (E/L) lamps. E/L lamps are custom-manufactured with very thin layers of plastic film with a transparent conductive surface with encapsulated phosphors that illuminate when energized.
For best lighting aesthetic appearance, mount the E/L lamp directly behind the graphic overlay and in front of metal switch domes and EMI shield. Proper selection of E/L lamp materials and construction, graphic overlay material and metal switch domes can give a good tactile feel for the end user.
Electroluminescent Lamp Backlighted Features & Options
- The electroluminescent lamp user interface includes a graphic overly, E/L lamp, optional EMI shield, metal switch domes, and printed circuit board.
- Lighting is cool to the touch as the light source is the energized phosphors.
- The electroluminescent lamp has the electrical characteristics of a capacitor so power dissipation (heat) is minimal.
- E/L drive voltage is in the range of 80 to 120 VAC with higher illumination level at 400 to 500 Hz, although useful illumination is available at 60 Hz.
- Custom E/L manufacturing process can provide for limited or customized areas of illumination or for individually driven areas of illumination with multiple E/L drive voltage control.
- E/L brightness increases with higher driving voltage and frequency but E/L life is decreased. E/L brightness gradually decreases with use. Useful live is considered to be a decrease to about 50% of initial brightness and is in the range of several thousand hours.
- E/L lamps operate from inverter modules that operate from available DC voltages found in most electronic applications.
- Most inverter modules can compensate for E/L lamp aging by adjusting the drive level to offset some of the reduced illumination.
- E/L lamps make the most sense when the E/L lamp switches off when not needed or activated by any user interface switch press.
- Electroluminescent Lamp Colors Include: White, Aviation White, Light Green, Light Red, Light Yellow, Light Blue
The above image depicts a typical electroluminescent lamp backlighted user interface.