Segmented Flexible Light Guide Air Pocket Refraction
Solution Overview
Problem
Existing segmented flexible light guides face challenges in achieving homogeneous lighting due to unwanted light bleeding and intensity spikes near LEDs, which require large distances between LEDs and light emitting sections, leading to increased system size and reduced efficiency.
Innovation Solution
The proposed solution involves creating a light guide with an air pocket at the LED to refract light, reducing the distance between the LED and the light emitting section to less than 5 mm, and using opaque and transparent sections made of thermoplastic polyurethane (TPU) to form a single layer light guide, which reduces light bleeding and enhances homogeneity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If large spacing is used between LED and light emitting section, then light homogeneity is improved, but system area increases
Solution Approach 1:
The patent introduces an air pocket as an intermediary medium between the LED and the light guide. This air pocket creates refraction at the interface, which helps to homogenize the light distribution and reduce the intensity spike near the LED, allowing for reduced spacing while maintaining homogeneity.
Solution Approach 2:
The patent changes the optical parameters at the LED interface by creating an air pocket, which alters the refraction index and light distribution characteristics. This parameter change enables the system to achieve homogeneous lighting at shorter distances without increasing system area.
2Illumination intensity
If light diffusion and absorption are increased to achieve homogeneity, then light distribution is improved, but brightness is considerably reduced
Solution Approach 1:
The air pocket acts as an optical intermediary that refraction light at the LED interface, achieving homogeneity without the need for strong diffusion or absorption materials. This preserves brightness while improving uniformity.
3Object-generated harmful factors
If opaque and transparent sections are fused to form single layer light guide, then light bleeding is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent uses composite TPU materials with different optical properties (opaque and transparent sections) fused together in a single layer. This composite structure effectively blocks light bleeding between neighboring sections while maintaining flexibility and integrated manufacturing.
Solution Approach 2:
The patent merges opaque and transparent TPU sections into a single integrated layer through fusion bonding. This combining approach reduces light bleeding while simplifying the overall structure compared to separate components, and enables flexible manufacturing.
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 design achieves significant improvement in lighting homogeneity, allowing for reduced distances between LEDs and light emitting sections, while maintaining efficient light distribution and reducing unwanted light bleeding between neighboring icons.
Implementation Method 1
an air pocket is provided at the LED that provides refraction of light at the interface with the light guide
Data Source
Figure 1A~1C
Figure 2A
Figure 2B
AI summary
Illuminating sections of a light guide with LEDs leads to unwanted light bleeding to other parts of the light guide. Furthermore typically LEDs are placed at a large distance from the area that couples out light from this LED due to a spike in intensity close to the LED. In order to avoid this spike being visible in the lit area the distance is increased which results in unwanted areal increase of the overall system. The present provides a layout to overcome these challenges.