directbacklit

Direct backlighting is a method of illuminating displays, notably LCDs, where the backlight sits directly behind the light-emitting layer rather than along the edges. The light source is typically an array of LEDs arranged behind the panel, often with diffusion layers and a light guide plate to create a uniform luminance across the screen. When combined with local dimming technology, direct backlighting enables precise control of brightness in different screen zones, improving contrast and black levels particularly in HDR content. The approach is commonly referred to as direct-lit LED or full-array backlighting, and it is commonly contrasted with edge-lit configurations that place LEDs along the frame and distribute light via a light guide.

Direct backlighting offers several advantages. It tends to provide more uniform illumination across the panel, reducing hotspots and allowing higher peak brightness without sacrificing uniformity. It also enables stronger local dimming, which can yield higher contrast ratios and deeper blacks in darker scenes. For large televisions and high-end computer monitors, direct backlighting with a full-array LED arrangement is a common design choice.

However, direct backlighting has drawbacks. It generally requires a thicker, heavier display and can be more expensive due to the LED array, diffusion layers, and more complex power and heat management. Power consumption can be higher, though LED efficiency has mitigated this in many designs. In portable devices where slimness is prioritized, edge-lit designs remain common.

See also: LCD backlight, edge-lit LED, full-array local dimming.