Optical Sensor Anti-Reflective Layer Curvature Light Trapping

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional touchscreen optical sensors face challenges in enhancing light absorption and signal detection, especially under low light conditions, due to reflective issues with anti-reflective layers.

Innovation Solution

The optical sensor design includes a substrate with a transistor, first and second electrodes, and an anti-reflective layer featuring U-shaped and convex portions that conform to the electrodes, enhancing light absorption and signal detection by minimizing reflection and trapping incident light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a conventional anti-reflective layer is used, then the device structure is simple, but light absorption is insufficient and reflection occurs

Engineering Contradiction:

Improvelight absorption efficiencyVSAvoidanti-reflective layer structure

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The anti-reflective layer incorporates a convex portion with a curved surface that protrudes from the substrate. This curvature design enables the layer to receive incident light from various directions and trap light within the U-shaped groove, significantly improving light absorption efficiency and reducing reflection compared to conventional flat anti-reflective layers.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The anti-reflective layer is segmented into distinct functional portions: a U-shaped groove portion that lines the electrode and a convex portion that protrudes outward. This segmentation allows each portion to perform its specific function - the U-shaped portion provides baseline anti-reflection while the convex portion actively captures and traps incident light from multiple angles.

Inventive Principle:

Principle #1Segmentation

2Loss of energy

If the anti-reflective layer is made thicker to improve light absorption, then light absorption improves, but the device thickness increases

Engineering Contradiction:

Improvelight absorption efficiencyVSAvoiddevice thickness

Core Design Contradiction:

Loss of energyVSLength of stationary object

Solution Approach 1:

Instead of simply increasing the thickness of a flat anti-reflective layer, the invention adds a convex portion that protrudes from the substrate surface in the vertical dimension. This creates a three-dimensional structure where the convex portion's curved surface intercepts light from various angles, achieving enhanced light absorption without requiring a uniform increase in overall device thickness.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The convex portion's curved surface geometry allows it to effectively interact with incident light from multiple directions. The curvature enables light trapping within the U-shaped groove structure, achieving superior light absorption efficiency with a relatively compact thickness profile compared to conventional flat designs.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Loss of energy

If a flat anti-reflective layer is used, then manufacturing is simple, but light from various directions cannot be effectively absorbed

Engineering Contradiction:

Improvelight absorption from various directionsVSAvoidanti-reflective layer fabrication

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The convex portion with its curved surface is designed to protrude from the substrate, creating a three-dimensional light-trapping structure. This curvature enables the anti-reflective layer to effectively receive and absorb incident light from various directions, overcoming the limitation of flat layers that only efficiently absorb light from perpendicular angles.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The anti-reflective layer is divided into a U-shaped groove portion conforming to the electrode and a convex portion protruding outward. This segmentation allows the convex portion to specifically address multi-directional light absorption while the U-shaped portion maintains electrical isolation, with both portions manufacturable through standard semiconductor fabrication processes.

Inventive Principle:

Principle #1Segmentation

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 configuration of the anti-reflective layer with a convex portion and U-shaped structure improves light absorption from various directions, enhancing signal detection and reducing reflection, particularly under low light conditions.

Implementation Method 1

enhancing light absorption and signal detection by minimizing reflection and trapping incident light

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 2

improves light absorption from various directions, enhancing signal detection and reducing reflection

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS10777603B1Optical sensor

Publication Date: 2020.09.15 INT TECH CO LTD

AI summary

An optical sensor is provided. The optical sensor includes a substrate, a transistor, a first electrode, a photodiode, a second electrode and an anti-reflective layer. The transistor is disposed over the substrate. The first electrode is disposed over the substrate and electrically connected to the transistor. The second electrode is disposed over the first electrode, and the photodiode is disposed between the first electrode and the second electrode. The anti-reflective layer is disposed over the second electrode and a first U-shaped portion lining the second electrode.