Light Guide Plate with Varying Linearity Adjustment for Uniform Backlight
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Solution Overview
Problem
Existing liquid crystal display backlights face issues with luminance uniformity due to irregular diffusion of light by vertical prisms, leading to reduced light use efficiency and the formation of dark stripes and local bright areas.
Innovation Solution
A lighting device with a light guide plate featuring elongated light collecting sections that adjust the linearity of light rays, including first and second light collecting regions with varying degrees of linearity adjustment, to ensure consistent light travel direction and reduce light diffusion parallel to the entering surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If vertical prisms are used to guide light rays perpendicular to the light entering surface, then light use efficiency is improved, but luminance uniformity deteriorates due to dark stripes and local bright areas
Solution Approach 1:
The patent applies local quality by configuring different regions of the light guide plate with different optical properties. Specifically, a first region near the light entering surface uses vertical prisms for efficient light guidance, while a second region farther from the light entering surface uses a diffuse reflecting layer to scatter light and eliminate dark stripes. This spatial differentiation of optical characteristics resolves the contradiction between light efficiency and luminance uniformity.
2Loss of energy
If vertical prisms are configured for straight light travel, then light use efficiency increases, but dark stripes become more visible due to reduced light diffusion
Solution Approach 1:
The patent implements local quality by creating distinct optical zones: the first region maintains vertical prism structures for straight light travel and high efficiency, while the second region introduces a diffuse reflecting layer that scatters light to mask dark stripes. This localized differentiation allows each region to optimize for its specific function without compromising overall performance.
3Illumination intensity
If light diffusion is increased to reduce dark stripes, then luminance uniformity improves, but light use efficiency decreases due to overlapping light paths
Solution Approach 1:
The patent resolves this contradiction by applying local quality through spatial zonation. The first region maintains minimal diffusion with vertical prisms to preserve light efficiency, while the second region applies diffuse reflection only where needed to uniformity. This targeted approach prevents unnecessary light scattering and overlapping in regions where straight light paths are already sufficient.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Improves luminance uniformity by directing light rays efficiently, minimizing dark stripes and bright spots, and enhancing overall light use efficiency.
Implementation Method 1
The light guide plate guides rays of light
Implementation Method 2
The light entering prism may guide some of rays of light from the light sources in a first direction and the rest of rays of light in a second direction
Implementation Method 3
The light collecting sections perform linearity adjustment to the rays of light so that the rays of light travel along the first direction
Data Source
AI summary
A lighting device includes light sources and a light guide plate. The light guide plate includes a base portion and a light collecting portion. The base portion includes a light entering surface and a light exiting surface. The light collecting portion protrudes from the light exiting surface. The light collecting portion includes light collecting sections elongated in a first direction parallel to a normal direction to the light entering surface and arranged in a second direction perpendicular to the first direction. The light collecting sections perform linearity adjustment to rays of light so that the rays of light travel along the first direction. The light collecting sections include first light collecting regions and second light collecting regions. The second light collecting regions perform the linearity adjustment at a degree greater than a degree of the linearity adjustment by the first light collecting regions.