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.
At a Glance: Electroluminescent Lamp Backlighted User Interfaces
- Electroluminescent (E/L) lamps provide thin, uniform backlighting for membrane switch user interfaces, delivering even illumination across graphic overlays with minimal heat generation.
- E/L backlit interfaces combine a graphic overlay, E/L lamp, optional EMI shield, metal switch domes, and PCB to create a visually appealing interface with positive tactile feedback.
- Available in multiple colors including White, Aviation White, Light Green, Light Red, Light Yellow, and Light Blue, with custom illumination zones and individually controlled lighting areas available.
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.
Frequently Asked Questions
Quick Links
- How does an electroluminescent lamp provide backlighting?
- What are the advantages of electroluminescent backlighting?
- What voltage is required to operate an electroluminescent lamp?
- How long do electroluminescent lamps last?
- Can electroluminescent lamps be used with DC-powered systems?
How does an electroluminescent lamp provide backlighting?
E/L lamps use thin layers of plastic film with a transparent conductive surface and encapsulated phosphors. When energized with AC voltage, the phosphors emit light, creating uniform illumination behind the graphic overlay.
What are the advantages of electroluminescent backlighting?
E/L backlighting provides cool, even illumination, low heat generation, minimal power dissipation, a thin profile, and the ability to create custom lighting areas within a user interface.
What voltage is required to operate an electroluminescent lamp?
E/L lamps typically operate at 80 to 120 VAC. Higher illumination levels are achieved at frequencies of 400 to 500 Hz, although usable illumination is available at 60 Hz.
How long do electroluminescent lamps last?
Brightness gradually decreases with use. Useful life is generally defined as the point when brightness falls to approximately 50% of its original level, which typically occurs after several thousand hours of operation.
Can electroluminescent lamps be used with DC-powered systems?
Yes. E/L lamps operate through inverter modules that convert available DC voltages into the AC drive voltage required by the lamp. Many inverter modules can also compensate for lamp aging by adjusting the drive level to help maintain illumination.
Need a Backlit HMI Solution?
Optimize your user interface with Epec's custom-manufactured Electroluminescent (E/L) lamps. Enjoy cool, even lighting with minimal power dissipation. Enhance tactile feel and visual appeal today. Consult us for a tailored solution.
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