Multi-Lens Optical System for UGR and Luminance Control
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Solution Overview
Problem
Existing lighting devices struggle to effectively control the Unified Glare Rating (UGR) and luminance, especially when the emitting surface is small, as they fail to provide clear 'cut offs' to meet regulatory requirements, leading to potential exceedance of UGR and luminance limits.
Innovation Solution
A lighting device equipped with a multi-lens optical system featuring plano-convex lenses and a grid structure, where the grid limits the angle of incidence and shapes the exit surfaces to ensure light rays are refracted at angles below the regulatory threshold, preventing total internal reflection and achieving controlled emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a prismatic plate with cones is used to control light emission, then UGR and luminance are controlled effectively for large emitting surfaces, but clear cut offs cannot be achieved when the emitting surface is very small
Solution Approach 1:
The optical element is segmented into a multi-lens array where each lens corresponds to a light-emitting element. This segmentation allows independent control of light paths from each LED, enabling precise angular control and clear cut offs even when the overall emitting surface is small. Each lens acts as an independent optical unit that can be optimized for its specific light source.
Solution Approach 2:
The exit surfaces of the lenses are designed with specific local geometries (planar, convex, concave, or asymmetric) tailored to the requirements of each light-emitting element. This local optimization ensures that each lens provides the appropriate light distribution and angular control for its specific position and function, achieving clear cut offs and regulatory compliance across the entire array regardless of overall surface size.
2Use of energy by moving object
If conventional optical elements are used, then light extraction from LEDs is achieved, but additional optics on light sources are required and clear cut offs cannot be ensured
Solution Approach 1:
The optical element combines multiple functions into a single integrated component: light extraction enhancement, angular distribution control, UGR reduction, and luminance control. By merging these functions into one element positioned away from the LED, the patent eliminates the need for separate optics on each light source while achieving clear cut offs and regulatory compliance.
Solution Approach 2:
The optical element acts as an intermediary between the light-emitting elements and the surrounding environment. It receives light from multiple LEDs, processes it through its lens array structure, and delivers controlled light distribution to the room. This intermediary approach consolidates multiple optical functions into a single component, reducing overall system complexity.
3Area of stationary object
If the emitting surface is very small, then device size is reduced, but UGR and luminance exceed law limits with conventional systems
Solution Approach 1:
The multi-lens array segments the optical control function across multiple lens units, each contributing to the overall light distribution control. This segmentation allows the system to achieve regulatory compliance even with a small overall emitting surface, as each lens independently controls its portion of the light output to ensure UGR and luminance remain within legal limits.
Solution Approach 2:
The patent controls critical parameters (UGR, luminance, emission angles) through the geometric parameters of the lenses (curvature, size, spacing, orientation). By optimizing these parameters, the system achieves regulatory compliance with small emitting surfaces, as the optical control effectiveness does not scale with surface area when using the multi-lens array approach.
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 optical system enables efficient control of UGR and luminance, ensuring compliance with regulatory limits even with small emitting surfaces, providing a clear 'cut off' without requiring additional optics on the light source, and ensuring homogeneous emission.
Implementation Method 1
If, however, a light ray crosses a 'descending' surface 35 of cones 33 (figure 2), then the angle of incidence α is greater than the limit angle and a total internal reflection effect is achieved.
Implementation Method 2
the lenses 9 and in particular the exit surfaces 14 thereof are shaped so as to project the light rays that pass through the grid 10 with emission angles β
Data Source
Figure 1~2
Figure 3~4
AI summary
A controlled-emission lighting device (1) comprises at least one light source (2) and an optical system (4) for the control of UGR index and luminance; the optical system (4) comprises a multi-lens optical element (8) formed by a plurality of lenses (9) arranged side-by-side along two directions, and a grid (10), located on an inner face (11), facing towards the light source (2), of the optical element (8); the grid (10) is dimensioned so as to limit the angle of incidence of the light rays that impinge on respective entry surfaces (13), facing towards the inside of the lighting device (1) and towards the light source (2), of the lenses (9); and the lenses (9) have respective exit surfaces (14) shaped so as to project the light rays passing through the grid (10) with emission angles lower than a threshold value.