Overlapping Light Guides with Prisms for Uniform Illumination
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Solution Overview
Problem
Display devices with overlapping light guides often experience non-uniform illumination luminance, which degrades the quality of the image displayed, due to variations in light intensity and chromaticity across the display area.
Innovation Solution
The configuration of a display device with two light guides and layers of prisms, where the light guides are displaced in the Y-direction, and the prisms are arranged to refract and diffuse light uniformly across the display panel, preventing non-uniformity by ensuring that light from each source is evenly distributed and mixed before reaching the panel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If two light guides overlap each other to provide illumination, then the illumination area is increased, but non-uniformity in luminance occurs across the display area
Solution Approach 1:
The illumination system is divided into multiple light guides (first light guide and second light guide) that are arranged in different layers. Each light guide is independently controlled and optimized, allowing the overall illumination area to be increased while maintaining uniform luminance through individual optimization of each segment.
Solution Approach 2:
The patent transitions from a single-layer light guide configuration to a multi-layer overlapping configuration. By adding the vertical dimension (stacking light guides in different layers), the illumination area is expanded while the uniformity problem is addressed through careful design of each layer's light guide geometry and light source arrangement.
2Area of stationary object
If light guides are arranged to cover the entire display area, then illumination coverage is improved, but chromaticity deviations and non-uniformity increase
Solution Approach 1:
Different regions of the display area are illuminated by different light guides or different portions of light guides, with each region optimized for its specific requirements. The first and second light guides can have different light source configurations, geometries, and optical properties tailored to achieve uniform chromaticity across their respective coverage areas.
Solution Approach 2:
The patent optimizes various parameters including the geometric shapes of the light guides, the positions and types of light sources, and the overlapping configurations to achieve uniform chromaticity. By carefully adjusting these parameters, the illumination coverage is maximized while chromaticity deviations are minimized across the entire display area.
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
This configuration ensures uniform luminance distribution across the display area, preventing streaky non-uniformity and chromaticity deviations, thereby enhancing the display quality by ensuring consistent illumination.
Implementation Method 1
the prisms are arranged to refract and diffuse light uniformly across the display panel
Implementation Method 2
The light emitted from the light source enters the light guide from a side surface of the light guide, passes through the light guide and is emitted from an emission surface
Data Source
AI summary
According to one embodiment, an illumination device includes first and second light guides, first and second light sources, and first and second layers. The first light guide includes first and second main surfaces and first and second side surfaces. The second light guide includes third and fourth main surfaces and third and fourth side surfaces. The first light sources face a second side surface. The second light sources face the third side surface. The first layer includes first prisms in the second main surface. The second layer includes second prisms in the fourth main surface. The second and fourth side surfaces are displaced from each other in a first direction.