Asymmetric Biconic LED Lens for Touch Panel Detection
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Solution Overview
Problem
Traditional SMD LEDs with symmetric lighting patterns are not suitable for touch panels as they result in reduced detecting sensitivity and signal crosstalk, leading to a short detecting distance and potential screen scratches, while also providing insufficient light brightness towards the user's eyes.
Innovation Solution
A manufacturing method to create light emitting units with a biconic lens structure that projects an asymmetric lighting pattern by cutting a dome-shaped packaging structure along specific axes, enhancing detection distance and light intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional SMD LEDs with symmetric lighting pattern are used, then the light intensity is distributed equally in two directions, but the detecting sensitivity is reduced and signal crosstalk occurs
Solution Approach 1:
The patent applies asymmetry by designing a lens structure with different curvature radii in the first and second directions. The lens has a first curvature radius in the first direction and a second curvature radius in the second direction, where the two curvature radii are different. This asymmetric lens structure directs light intensity preferentially in the vertical direction (toward the user's eyes) while reducing lateral light projection, thereby improving touch panel detecting sensitivity and eliminating signal crosstalk that occurs with symmetric lighting patterns.
2Reliability
If traditional SMD LEDs with symmetric lighting pattern are used, then the lighting pattern is simple, but the detecting distance is short
Solution Approach 1:
The patent employs an asymmetric lens structure with different curvature radii in orthogonal directions to extend the detecting distance of the touch panel. The lens is configured with a first curvature radius in the vertical direction and a second curvature radius in the horizontal direction, creating an asymmetric light distribution that concentrates light intensity toward the user's eyes while reducing lateral projection. This design extends the effective detection distance without requiring complex multi-component systems.
3Illumination intensity
If traditional SMD LEDs are used, then the manufacturing process is simple, but the light brightness toward user's eyes is insufficient
Solution Approach 1:
The patent solves the brightness issue by implementing an asymmetric lens structure that concentrates light intensity in the vertical direction toward the user's eyes. The lens has different curvature radii: a first curvature radius in the vertical direction and a second curvature radius in the horizontal direction. This asymmetric configuration redirects more light intensity upward, ensuring adequate brightness for the user while maintaining a manufacturable single-lens structure that can be integrated with existing LED packages.
4Object-affected harmful factors
If traditional SMD LEDs with symmetric lighting pattern are used, then the light distribution is uniform, but screen scratches may occur due to reduced detecting distance
Solution Approach 1:
The patent addresses the screen scratch issue by using an asymmetric lens structure that extends the detecting distance, allowing users to position their fingers farther from the screen while still achieving reliable touch detection. The lens directs light intensity preferentially in the vertical direction, creating a detection zone that extends farther from the screen surface. This reduces the need for users to press their fingers close to the screen, thereby minimizing mechanical contact and potential scratches.
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 asymmetric lighting pattern improves touch panel detection sensitivity and extends the detecting distance, while ensuring adequate light brightness for the user, reducing signal crosstalk and screen wear.
Implementation Method 1
a biconic lens structure having a top surface and two pair of side surfaces, the top surface is a biconic surface... the light emitting unit has an asymmetric lighting pattern in two directions
Data Source
AI summary
A manufacturing method of light emitting units is shown below. First step is providing a substrate with multi circuit areas. A light emitting diode is mounted on the circuit area respectively. Next step is forming a package structure to cover the light emitting diode. Next step is dicing the package structure to form a biconic package structure. The package structure is diced twice in two directions, respectively. As above-mentioned, the light emitting unit has asymmetric light radiation pattern.