One-Way Filtered Exterior Display for Sunlight Contrast
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Solution Overview
Problem
External light-emitting systems, such as vehicle displays, face challenges in maintaining contrast in bright ambient light conditions due to the washing out effect of sunlight, which reduces the visibility of displayed information.
Innovation Solution
The implementation of a one-way filter with a microlens array and a masking layer in the exterior display system, where the microlens array collimates light and focuses it through holes in the masking layer, allowing display light to pass while blocking ambient sunlight, thereby preserving contrast and reflecting sunlight away from the viewer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional light-emitting display is used without filtering, then the display structure is simple and manufacturing is easier, but the contrast deteriorates in bright ambient light conditions
Solution Approach 1:
The one-way filter is segmented into multiple functional layers: a microlens array layer that collimates and focuses light, and a masking layer with holes that blocks ambient light. This segmentation allows each layer to perform its specific function optimally, achieving high contrast while maintaining a manageable structure.
Solution Approach 2:
The microlens array and masking layer are nested together to form an integrated one-way filter assembly. The microlenses are positioned to focus light through the holes in the masking layer, creating a compact nested structure that achieves complex optical functionality without proportionally increasing overall device complexity.
2Illumination intensity
If a one-way filter with microlens array and masking layer is implemented, then display contrast is maintained in bright sunlight, but the device complexity increases
Solution Approach 1:
The microlens array provides local quality control by directing light through specific holes in the masking layer. Each microlens focuses light locally through its corresponding hole, while the masking layer blocks ambient light in non-hole areas. This local quality approach achieves high contrast without requiring the entire filter structure to be uniformly complex.
Solution Approach 2:
The microlens array acts as an intermediary between the light source and the masking layer. It collimates the emitted light and focuses it through the holes in the masking layer, mediating the interaction between the light-emitting elements and the ambient light blocking function. This intermediary role enables the system to achieve high contrast while managing the complexity of the overall filter structure.
3Illumination intensity
If the masking layer uses black material to block ambient light, then contrast is improved, but the off-state appearance is limited to black only
Solution Approach 1:
The masking layer material parameters can be changed to achieve different off-state appearances. Instead of being limited to black materials, the masking layer can use materials with different colors, translucency levels, or reflective properties. This parameter change approach maintains the light blocking function while providing versatility in aesthetic appearance for different applications.
Solution Approach 2:
The masking layer is designed to serve multiple functions: blocking ambient light to maintain contrast, and providing customizable off-state appearance. By making the masking layer material selectable from various options (black, colored, translucent, reflective), it becomes a universal component that satisfies both functional and aesthetic requirements across different display applications.
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 solution effectively maintains high contrast for the exterior display even in bright sunlight conditions, ensuring that the displayed information remains visible and clear, while also providing options for different appearances of the display in its off state, such as black or mirror-like finishes.
Implementation Method 1
The collimator is configured to collimate light from the array of light-emitting diodes
Implementation Method 2
The microlens array in the one-way filter receives the collimated light and focuses the collimated light through a plurality of holes in the masking layer
Implementation Method 3
the majority of ambient sunlight is blocked by the masking layer, thus preserving a high contrast for the exterior display even in bright sunlight
Implementation Method 4
the masking layer may have a high specular reflection. With this type of arrangement, ambient sunlight is reflected towards the ground (away from the viewer) to preserve display contrast and the display has a mirror-like appearance in the off state
Data Source
AI summary
A system may have an exterior display. The exterior display may display symbols that correspond to intended actions for the system or instructions for nearby viewers. The exterior display may include an array of light-emitting diodes, a collimator, a one-way filter to prevent sunlight from washing out the display, and a cover layer. The one-way filter may include a microlens array and a masking layer. The collimator is configured to collimate light from the array of light-emitting diodes and provide the collimated light to the one-way filter. The microlens array receives the collimated light and focuses the collimated light through a plurality of holes in the masking layer. In this way, the majority of display light is passed through the one-way filter towards a viewer. However, the majority of ambient sunlight is blocked by the masking layer, thus preserving a high contrast for the exterior display even in bright sunlight.