Optical Plate Micro Lens Array Reduces Glare
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Solution Overview
Problem
Conventional indoor flat lighting devices fail to meet the Unified Glare Rating (UGR) standard of less than 19 due to the wide light spreading angle, even when using diffusion plates, resulting in visual discomfort and glare.
Innovation Solution
An optical plate with a micro lens array patterned on a transparent substrate, featuring a fill factor of 0.5 to 1.0 and sag of 0.1 to 0.5, is used to reduce the light flux emitted between 65 degrees and 90 degrees, combined with a diffusion unit and condensing unit in an illuminating member to minimize glare.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a diffusion plate is used to reduce hot spot and emit uniform light, then light uniformity is improved, but light is scattered up to 65-90 degrees causing glare and high UGR
Solution Approach 1:
The diffusion plate is segmented into multiple regions with different diffusion coefficients. The first region (central area) has a first diffusion coefficient while the second region (peripheral area) has a second diffusion coefficient that is different from the first, allowing different parts of the light to be diffused to different extents to control glare angles
Solution Approach 2:
Different regions of the diffusion plate are assigned different optical properties (diffusion coefficients). The central region and peripheral region have distinct diffusion characteristics tailored to their specific functions: the central region controls hot spot diffusion while the peripheral region controls glare reduction
2Object-affected harmful factors
If a reflecting shade or louver is used to reduce light spreading angle, then UGR is reduced mechanically, but the device becomes less aesthetic and cannot achieve perfect flat lighting
Solution Approach 1:
The mechanical reflecting shade or louver system is replaced with an optical diffusion plate system. Instead of using physical barriers to block and redirect light, the invention uses optical diffusion with spatially varying diffusion coefficients to achieve both UGR reduction and aesthetic flat lighting appearance
3Object-affected harmful factors
If the whole lighting device is buried to reduce light spreading angle, then UGR is reduced, but the light efficiency and brightness are compromised
Solution Approach 1:
The diffusion plate is divided into regions with different diffusion coefficients, allowing optimized light distribution. This segmentation enables maintaining higher light efficiency by directing more light in useful directions while still reducing glare, compared to complete burial of the lighting device
Solution Approach 2:
The diffusion coefficient is changed spatially across different regions of the diffusion plate. By varying this optical parameter from the first diffusion coefficient in the central region to the second diffusion coefficient in the peripheral region, the system optimizes both UGR reduction and light efficiency
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 effectively reduces UGR values to meet the standard of less than 19, enhancing lighting comfort by minimizing glare and maintaining light efficiency.
Implementation Method 1
an optical plate having a structure in which a micro lens array is patterned on a transparent plate
Implementation Method 2
a diffusion unit for diffusing and radiating light incident from a light source
Data Source
AI summary
Disclosed is an optical plate and an illuminating member, and particularly an optical plate for reducing UGR, which has a plurality of micro lens patterns formed on a base substrate, a fill factor of the micro lens patterns being in range of 0.5 to 1.0.