Polygonal Light Guide Plate Recessed Portion for Uniform Illumination

The patent applies local quality by creating a recessed portion at specific locations (corners or edges) of the light guide plate where light enters. This localized structural modification changes the refractive index distribution and light propagation characteristics in specific regions, enabling effective light diffusion even when the overall module thickness is reduced. The recessed portion acts as a local optical structure that enhances light scattering without requiring increased distance from the light source to the emission face.

The patent introduces a vertical dimension by creating a recessed portion that extends into the light guide plate thickness direction. This dimensional change creates an air-filled cavity or low refractive index region that disrupts light propagation in the thickness direction, causing light to scatter laterally. This vertical structural modification enables improved light diffusion without increasing the horizontal footprint or requiring the light source to be positioned farther away, thus maintaining thin module design while achieving uniform illumination.

The recessed portion creates a localized optical structure that enhances light scattering and mixing in specific regions of the light guide plate. By positioning these recessed portions at corners or edges, the patent ensures that light from the LED array is effectively diffused across the entire emission surface, including areas that would otherwise receive insufficient scattered light. This local structural modification promotes uniform color distribution without requiring increased module thickness.

The air-filled recessed portion acts as an intermediary optical element between the light source and the emission face. This intermediate structure with different refractive index properties facilitates light scattering and color mixing by creating additional light-path interactions. The recessed portion mediates the light propagation process, enabling effective color uniformity even when the distance between the light source and emission face is minimized for thin module design.

The patent applies segmentation by dividing the light guide plate into distinct regions: flat areas and recessed portions. The recessed portions are strategically positioned at corners or edges rather than uniformly distributed, creating a segmented structure that simplifies manufacturing compared to complex continuous patterns. This segmented approach achieves effective light diffusion by focusing optical modification only where most needed, reducing overall structural complexity while maintaining uniform illumination.

The patent employs asymmetry by positioning recessed portions specifically at corners or edges of the light guide plate rather than symmetrically distributing them across the entire surface. This asymmetric placement optimizes light diffusion effectiveness by targeting regions that naturally receive less scattered light. The asymmetric design simplifies the overall structure compared to symmetric patterns while achieving superior luminance and color uniformity.