Many devices feature electroluminescent (EL) backlighting. Switches and keypads, for instance, often feature this type of backlighting. EL backlighting will illuminate the switch or keypad so that the buttons or legends are easier to see. While EL backlighting is available in different configurations, however, they all use phosphor. Without phosphor, they wouldn’t be able to produce light and illuminate the switches and keypads with which they are used.

What Is Phosphor?

Phosphor is a compound that exhibits the property of luminescence. When exposed to electrical energy, it emits light. Phosphor has the unique ability to produce light in response to electrical energy, which is the basis of how it works in EL backlighting.

Phosphor is often made of different materials. Some types of phosphor are made of metal, whereas others are made of organic compounds. Different types of phosphor are also used to create different colors of light. There’s blue, green and red phosphor, each of which produces a unique color.

Why EL Backlighting Uses Phosphor

When most people think of backlighting, they envision diodes or bulbs. EL backlighting, though, uses a different approach to illuminate switches and keypads. Rather than diodes or bulbs, it features phosphor. EL backlighting leverages luminescence to produce light.

EL backlighting consists of two conductive layers. Between these two layers is phosphor. Since the layers are conductive, electricity can flow through them. Phosphor compounds, of course, are luminescent, so they will generate light when exposed to electrical energy. When you power up the switch or keypad, electricity will travel through the two layers and the phosphor compounds between them, thereby illuminating the switch or keypad.

Reasons to Choose EL Backlighting

There are other backlighting technologies available for switches and keypads, but EL backlighting is a popular choice for several reasons. It offers a low-profile design. Because there are no diodes or bulbs, EL backlighting consumes less space than other backlighting technologies. This allows for smaller, low-profile switches and keypads.

EL backlighting is also energy efficient. All backlighting technologies consume energy — and EL backlighting is no exception. The good news is that EL backlighting is one of the most energy-efficient backlighting technologies available.

Even brightness is another benefit of EL backlighting. It provides uniform illumination across the entire interface of the switch or keypad. Unlike cold-cathode fluorescent lighting (CCFL) backlighting, which can produce hotspots or uneven lighting, EL backlighting offers even brightness. This is just one more reason to choose EL backlighting for when ordering a switch or keypad.