LED Reflection Wall and Diffusion Sheet for Uniform Luminance
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Solution Overview
Problem
Existing surface light emitting devices face challenges in achieving uniform luminance due to non-uniform distribution of light emitted from LEDs, leading to luminance unevenness.
Innovation Solution
A light emitting device design incorporating a reflection wall surrounding the LED and a diffusion reflection sheet with particles to efficiently diffuse and reflect light, enhancing luminance uniformity by recirculating light within a defined region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple light emitting element is used, then device complexity is reduced, but luminance uniformity deteriorates
Solution Approach 1:
A diffusion reflection sheet is introduced as an intermediary component between the light emitting element and the surrounding environment. This sheet contains numerous small particles that scatter and diffuse the light, transforming the non-uniform light distribution from the simple light emitting element into a uniform luminance distribution across the surface.
Solution Approach 2:
The diffusion reflection sheet is positioned specifically at the light emitting surface where luminance uniformity is needed. The sheet contains particles with specific optical properties that locally modify the light distribution, creating uniform luminance in the region of interest without requiring complex modifications to the entire device structure.
2Illumination intensity
If the distance between LED and diffusion sheet is increased, then luminance uniformity is improved, but device size increases
Solution Approach 1:
Instead of increasing the distance between the LED and diffusion sheet to improve luminance uniformity, the invention changes the optical parameters of the diffusion sheet itself by incorporating particles with specific scattering properties. This allows achieving uniform luminance at short distances by modifying the light interaction characteristics rather than changing geometric dimensions.
Solution Approach 2:
The diffusion reflection sheet is constructed as a composite material containing numerous small particles embedded in a reflective matrix. This composite structure enables effective light diffusion and uniform luminance generation within a compact thickness, avoiding the need for large air gaps or extended distances.
3Device complexity
If light is allowed to escape directly from the light emitting element, then device complexity is reduced, but heat generation increases
Solution Approach 1:
The diffusion reflection sheet acts as an intermediary layer that intercepts light from the light emitting element before it can escape directly. The sheet reflects and diffuses the light, preventing direct escape paths that would carry heat away from the device, thereby containing thermal energy within the compact structure.
Solution Approach 2:
Instead of allowing light (and associated heat) to escape directly from the light emitting element, the diffusion reflection sheet recovers and redirects the light through multiple reflections and scattering events. This process traps the thermal energy within the device structure, converting what would be wasted heat into contained thermal energy that can be managed more effectively.
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 achieves high luminance uniformity within the region surrounded by the reflection wall, reducing the distance between the LED and the diffusion sheet, and maintaining a low profile while minimizing heat generation and cost.
Implementation Method 1
In the diffusion reflection sheet, the entering light is efficiently diffused by and reflected from the plurality of the particles
Implementation Method 2
a reflection wall that surrounds the light emitting element
Data Source
AI summary
A light emitting device includes: a light emitting element; a reflection wall that surrounds the light emitting element; and a diffusion reflection sheet that includes a plurality of particles and permits entrance of emitted light from the light emitting element and reflected light from the reflection wall.