Transparent Roof Panel Light Outcoupling With Daylight Transparency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing transparent roof panel assemblies for vehicles face challenges in providing functional illumination while minimizing obstruction of the view, especially during the day when the reflective dots are perceived as dark dots.
Innovation Solution
A transparent roof panel assembly with a very low pigment concentration in the ink (0.01-1.5%) allows for good daylight transparency even with larger dots or higher dot densities, while the scattering properties of the first layer ensure that images are visible from inside the vehicle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If large reflective dots are applied on the panel surface for light out-coupling, then functional illumination is achieved, but the view is obstructed during daytime when dots appear as dark spots
Solution Approach 1:
The patent changes the optical parameters of the dots by using semi-transparent or opaque materials with specific refractive indices and controlling dot diameter (smaller than 150 microns, preferably smaller than 80 microns) and surface coverage (smaller than 10%, preferably smaller than 5%). This allows the dots to effectively couple out light while remaining less visible during daytime, thus resolving the contradiction between illumination efficiency and view obstruction.
2Object-affected harmful factors
If dot coverage is reduced to improve transparency during daytime, then view obstruction is reduced, but design freedom for patterns and images is limited
Solution Approach 1:
The patent enables higher dot coverage and larger dot diameters by using materials with optimized refractive indices that reduce visibility during daytime. This parameter change in material properties allows designers to create more complex patterns, images, and text on the panel surface without excessively obstructing the view, thus restoring design freedom while maintaining transparency.
Solution Approach 2:
The patent employs semi-transparent or opaque dots with specific refractive indices that can be optimized to match or contrast with the panel background. This allows the dots to be less visible during daytime while still effectively coupling out light, enabling more versatile pattern design without excessive view obstruction.
3Illumination intensity
If pigment concentration in the ink is increased to improve light scattering and image visibility, then light out-coupling is enhanced, but transparency during daytime is reduced
Solution Approach 1:
The patent optimizes the pigment concentration in the ink to achieve a balance between light scattering efficiency and daytime transparency. By carefully controlling the refractive index of the ink components and their concentration, the patent enables effective light out-coupling and image visibility while maintaining good transparency during daytime, thus resolving the contradiction between illumination efficiency and transparency.
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 effective light out-coupling and image visibility from inside the vehicle, maintaining high transparency and reducing view obstruction, even in daylight conditions.
Implementation Method 1
a light source (104) arranged to provide light into a panel (102, 101, 103) to function as a light guide
Implementation Method 2
a light outcoupling pattern (106) arranged between the first main surface of the first transparent layer and the second transparent layer, wherein the light outcoupling pattern is configured for scattering at least a part of the light propagating in the first transparent layer
Data Source
AI summary
A transparent roof panel assembly for a vehicle roof comprises a panel and a light source. The panel comprises a first transparent layer having a first main surface and a second main surface opposite the first main surface, a second transparent layer arranged adjacent to the first main surface and a light outcoupling pattern arranged between the first main surface of the first transparent layer and the second transparent layer. The pattern is configured for scattering at least a part of the light from the light source such that light exits the first transparent layer through the second main surface. The pattern comprises scattering particles arranged in a transparent carrier. The particles are pigments in a white ink having a concentration of 0.01-1.5% by weight. The pattern may form an image having a contour formed by a full surface printing, a width being similar to dots forming the image.