Direct-Lit Backlight Layout for Thin Uniform HDR Displays

The patent removes the lens component from the backlight unit entirely. Instead of using a lens to spread light laterally, the invention uses a light guide plate with a specifically designed upper surface that directly guides and spreads light from the LED without requiring a separate lens element, thereby eliminating the thickness contribution of the lens while maintaining light uniformity

The patent changes the approach from using a lens (a three-dimensional optical element) to using a two-dimensional surface structure on the light guide plate. The upper surface of the light guide plate is designed with specific geometric features that spread light laterally through refraction and reflection at the surface, replacing the function of the lens in a different dimensional manner

The patent divides the backlight unit into distinct functional segments: a light guide plate that receives light from LEDs positioned at its lower surface, and an upper surface with specific geometric features that spread the light laterally. This segmentation allows the light guide plate to maintain a thin profile while the upper surface structure provides the light spreading function that was previously required of a lens

The light guide plate serves as an intermediary element between the LED light source and the display panel. Instead of using an edge type backlight where LEDs are positioned at the side, the light guide plate mediates by receiving light from LEDs at its lower surface and distributing it uniformly across the display area through its specially designed upper surface, enabling both thinness and uniform illumination