Display backlighting is used to illuminate LCDs (liquid crystal displays), as well as for machine vision, image scanning and task lighting. Unlike frontlights, which illuminate from the front, backlights usually produce illumination from the sides or from the back of the screen.

Types of display backlighting

You can choose from display backlighting in a range of colours (including white, green and yellow) and levels of brightness, depending on the application you need it for. The two main types of display backlight are:

• LED (light emitting diodes) backlighting – this uses 10 to 18 LEDs arranged in a uniform pattern and usually provides white light.
• CCFL (cold cathode fluorescent) backlighting – this uses a single straight glass tube, which works much like a normal fluorescent lamp.

Applications of display backlighting

As LCD screens are unable to illuminate themselves, they require a backlight to provide the illumination and make the image on the screen viewable. Apart from being used in computer displays, LCD televisions and smartphones, backlights are also used in small devices such as watches and pocket calculators to improve readability in low-light conditions.