Vehicle Roof Panel Light Guide Exterior Glow Reduction
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Solution Overview
Problem
Existing transparent roof panel assemblies for vehicles face challenges in reducing exterior light emission while maintaining light efficiency, as dark interlayers can absorb more light and affect the light guide's efficiency.
Innovation Solution
A multi-layered roof panel assembly is introduced, featuring a first transparent ply of rigid material, a second transparent layer of flexible material with lower transparency, and optionally a third transparent ply, along with functional layers for adjustable transparency and light management, including an optically switchable layer to control light transmission and visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a dark interlayer is provided to reduce exterior light emission, then exterior light level is reduced, but light efficiency of the light guide is affected due to light absorption
Solution Approach 1:
The panel is divided into multiple layers with distinct functions: the first transparent ply serves as the light guide, the first transparent layer provides structural support, and the second transparent layer with reduced transparency specifically targets exterior light emission. This segmentation allows each layer to optimize its function without compromising the others, particularly preserving light guide efficiency while reducing exterior glow.
Solution Approach 2:
The second transparent layer is positioned specifically on the exterior side of the panel with reduced transparency properties. This local modification of optical properties allows targeted reduction of exterior light emission without affecting the overall light transmission to the interior, thereby maintaining light guide efficiency while addressing the harmful exterior glow.
2Object-affected harmful factors
If a dark upper ply is provided to reduce exterior luminance level, then exterior light level is reduced, but visible light transparency to the interior is further reduced
Solution Approach 1:
The panel structure is segmented into multiple layers with differentiated optical properties. The second transparent layer with reduced transparency is specifically positioned to target exterior glow reduction, while the first transparent ply maintains high transparency for interior illumination. This segmentation enables independent optimization of exterior and interior optical performance.
Solution Approach 2:
The reduced transparency is locally applied in the second transparent layer that interfaces with the exterior environment. This localized optical property modification specifically addresses exterior luminance reduction while preserving the optical quality of the first transparent ply that serves interior illumination, thereby resolving the contradiction between exterior glow reduction and interior lighting.
3Object-affected harmful factors
If light transmission is reduced in the panel, then exterior light level and energy transmission are reduced, but interior illumination is also reduced
Solution Approach 1:
The panel is segmented into multiple layers with differentiated light transmission properties. The second transparent layer with reduced transparency specifically targets energy transmission and exterior glow reduction, while the first transparent ply maintains high light transmission for interior illumination. This segmentation allows independent control of energy management and interior lighting functions.
Solution Approach 2:
Reduced transparency properties are locally applied in the second transparent layer that interfaces with the exterior, creating a selective optical filter. This local modification reduces energy transmission and exterior glow while preserving the high light transmission quality of the first transparent ply that serves interior illumination, thereby resolving the contradiction between energy management and interior lighting.
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 allows for reduced visible light transparency, improved light efficiency, and adjustable lighting effects, minimizing exterior light emission while maintaining interior illumination, thus addressing the limitations of traditional assemblies.
Implementation Method 1
a light outcoupling pattern arranged between the first main surface of the first transparent ply and the first transparent layer, wherein the light outcoupling pattern is configured for scattering at least a part of the light propagating in the first transparent ply such that at least a part of the propagating light exits the first transparent ply through the second main surface
Implementation Method 2
functional layers for adjustable transparency and light management, including an optically switchable layer to control light transmission and visibility
Data Source
Figure 1~2
Figure 3A~3D
AI summary
A transparent roof panel assembly (100) for a vehicle roof (1) comprises a transparent panel and a light source (21; 104) arranged to provide light in the panel. The panel comprises a first transparent ply (101) of rigid material having a first main surface and a second main surface opposite the first main surface and a first transparent layer (103) of flexible material arranged adjacent to the first main surface. The light source is configured to provide light (105) in the first transparent ply such that at least a part of the light propagates between the first main surface and the second main surface through the first transparent ply. A light outcoupling pattern (106) is arranged between the first main surface of the first transparent ply and the first transparent layer. The light outcoupling pattern is for scattering at least a part of the light propagating in the first transparent ply such that at least a part of the propagating light (107) exits the first transparent ply through the second main surface. A second transparent layer (109) of flexible material is provided above the first transparent layer on a side thereof opposite to the first transparent ply, the second transparent layer (109) having a transparency which is less than that of the first transparent layer (103).