Electroluminescence Panel (ELP) Backlighting
Electroluminescence Backlights for LCD modules
EL (Electroluminescence) backlighting is also called an ELP (Electroluminescence Panel). This type of backlighting is a technology that uses colored phosphors, not heat, to generate light and can be added to many LCD technologies. The majority of Electroluminescence backlight technology is used in character, segment and monochrome graphic displays.
Electrical requirements
The electrical requirements for EL backlights used on these displays are 100VAC @ 400Hz which is supplied by an inverter that converts 5, 12 or 24 VDC input to the AC output.
Advantages of EL backlights
Thinness:
They are about the thickness of a credit card. This reduces the overall thickness of the LCD module for applications where the product must fit into a tight area.
Even light flow:
They produce an even light flow with no hot or cold spots, which eliminates the need for a diffuser to even out the spots of light that could be caused by other backlighting technology.
Variety of colors:
EL backlights are available in a variety of different colors.
Disadvantages of EL backlights
Small size:
They cannot be manufactured in larger sizes.
AC signal:
EL backlights require an AC (Alternating Current) signal which generates noise that can interfere with neighboring circuits. Also, the AC signal must be generated from a standard DC signal with an inverter that is supplied by the customer or included on the LCD module. The customer may need to shield their product to eliminate this interference.
Higher MOQs:
EL backlights are becoming less popular which is increasing the MOQ (minimum order quantity). At this time the MOQ is between 500 to 1K units per build.
Noise:
Sometimes EL backlights emit a humming that is caused from the inverters used on the board. A film capacitor can be used to prevent this noise. The customer may need to shield their product to eliminate this interference.
Half-life:
The half-life of EL backlights is much shorter than other backlighting technologies at 3k to 5k hours. This is much shorter than the half-life of LED (Light Emitting Diode) technology which has a half-life of 70K hours.
Half-life is when the backlight is ½ as bright as when it was first turned on. This is not when the backlight burns out.
New product designs
If you are designing a new product containing a LCD, we recommend not choosing a display with an Electroluminescence backlight. LED technology is the standard backlight option.
Replacement LCDs
Focus displays offers replacement LCDs, many of these older replacement displays contain an Electroluminescence backlight. We are still able to supply these displays, but may require a low NRE (tooling) cost.
Do you have questions about Electroluminescence Panel Backlighting? Contact us today at 480-503-5295.