Optical Lens Recessed V-Shape for LCD Uniformity
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Solution Overview
Problem
Liquid crystal display (LCD) devices with point light sources, such as LEDs, suffer from luminance and color uniformity issues due to the Lambertian distribution of light, leading to non-uniform illumination and image quality degradation.
Innovation Solution
An optical lens with a recessed part and a refracting part is used to cover the point light source, where the recessed part has a V-shaped cross-section and different radii to totally reflect light, and the refracting part refracts the reflected light to achieve uniform illumination, eliminating the need for a light guiding plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a point light source (LED) with Lambertian distribution is used, then the device size can be reduced, but luminance uniformity and color uniformity deteriorate
Solution Approach 1:
The optical lens is divided into multiple regions with different refractive indices or optical properties. The lens includes a first region, a second region, and a third region, each designed to control light distribution in specific angular ranges (0-30°, 30-60°, 60-90° respectively), transforming the uniform Lambertian distribution into a non-uniform distribution that achieves uniform luminance across the display area.
Solution Approach 2:
Different portions of the optical lens are assigned different optical characteristics to address specific uniformity issues in different spatial regions. The lens structure includes varying refractive indices or curvature radii in different zones, allowing each local region to optimize light redirection for its specific angular range, thereby achieving overall luminance and color uniformity.
2Device complexity
If a point light source (LED) with Lambertian distribution is used, then the device structure can be simplified, but color uniformity deteriorates
Solution Approach 1:
The optical lens performs multiple functions simultaneously: it redirects light from the point source, controls angular distribution, ensures luminance uniformity, and maintains color uniformity across the display area. This multi-functional design eliminates the need for separate light guiding plates or additional uniformity correction components, achieving color uniformity while keeping the structure simple.
Solution Approach 2:
The patent addresses the two-dimensional uniformity problem (luminance and color across the display area) by introducing a three-dimensional optical lens structure with varying refractive properties in different spatial zones. This dimensional approach allows control of light propagation in multiple angular dimensions simultaneously, achieving uniform color distribution without adding lateral components.
3Illumination intensity
If a light guiding plate is used to improve luminance uniformity, then luminance uniformity improves, but device size and complexity increase
Solution Approach 1:
The patent merges the functions of the light guiding plate and the optical lens into a single integrated optical lens component. The lens simultaneously performs light redirection, angular distribution control, and uniformity correction that would traditionally require separate components. This integration eliminates the need for a dedicated light guiding plate, reducing device size while maintaining luminance uniformity.
Solution Approach 2:
The optical lens is designed to perform multiple functions that would traditionally require separate components: it acts as both a light redirecting element and a uniformity correction element. By incorporating multiple functional zones within a single lens structure, the patent achieves the luminance uniformity benefits of a light guiding plate without requiring its presence, thereby reducing overall device size.
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
The solution significantly improves luminance and color uniformity by scattering light evenly, reducing the size of the device and enhancing image quality, while maintaining high luminance levels across the display.
Implementation Method 1
the recessed part has a V-shaped cross-section and different radii to totally reflect light
Implementation Method 2
the refracting part refracts the reflected light to achieve uniform illumination
Data Source
AI summary
An optical lens includes a recessed part and a refracting part. The recessed part has a substantially circular plan view and a substantially V shaped cross-section. The recessed part forms an angle of no more than an angle of about 20° with respect to a vertical line. The recessed part has a plurality of curved surfaces including different radii so that a light incident into the recessed part is totally reflected from the curved surfaces. The refracting part has a substantially circular plan view extended from the recessed part. A light incident into the refracting part and the reflected light from the recessed part are refracted from the refracting part. Therefore, a luminance uniformity and a color uniformity are improved.