Reverse Tapered Insulating Pattern for Display Sensor Integration
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Solution Overview
Problem
Existing display devices face challenges in efficiently integrating sensors for touch recognition or fingerprint recognition, particularly in reducing the width of light openings to enhance light travel to optical sensors.
Innovation Solution
A display device design that includes a substrate with emission and light sensing portions, a bank layer, and a touch sensing layer with a reverse tapered first touch insulating pattern and touch electrodes, which partitions a light opening and reflects incident light towards the light sensing portion for accurate fingerprint identification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the width of light opening is reduced to increase light travel efficiency to optical sensor, then light travel efficiency is improved, but light recognition accuracy deteriorates
Solution Approach 1:
The patent introduces a tilted touch insulating pattern that extends in the thickness direction (third dimension) rather than only in the planar direction. This three-dimensional structure creates a tilted light guide path that reflects light toward the optical sensor, effectively increasing light collection efficiency without reducing the light opening width, thus resolving the contradiction between light travel efficiency and recognition accuracy.
2Productivity
If the width of light opening is reduced to integrate sensors efficiently, then sensor integration efficiency is improved, but light collection capability worsens
Solution Approach 1:
The tilted touch insulating pattern acts as an intermediary optical element between the light source and the optical sensor. It functions as a light guide that redirects light paths, enabling efficient light collection even through a narrow light opening, thus maintaining both sensor integration efficiency and light collection capability.
3Device complexity
If touch electrode is positioned close to light sensing portion for compact design, then device compactness is improved, but light reflection to sensor deteriorates
Solution Approach 1:
The patent positions the touch electrode in close proximity to the light sensing portion but uses a tilted touch insulating pattern that extends into the thickness direction. This three-dimensional arrangement allows the touch electrode to be spatially close to the sensor while the tilted pattern creates an optical path that reflects light toward the sensor, maintaining both compactness and light reflection efficiency.
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 proposed solution effectively reduces the light opening width, enhances light reflection towards the light sensing portion, and improves the accuracy of fingerprint recognition in display devices.
Implementation Method 1
A cross-sectional shape of the first touch insulating pattern has a reverse tapered shape having a width that decreases in a direction towards a top surface of the substrate... capable of reflecting light incident through a light opening toward a light sensing portion
Data Source
AI summary
A device comprises a substrate, a plurality of emission portions disposed on the substrate and emitting light, a plurality of light sensing portions disposed on the substrate and sensing an incident light, a bank layer partitioning the plurality of emission portions and the plurality of light sensing portions, and a touch sensing layer disposed on the bank layer. The touch sensing layer comprises a first touch insulating pattern disposed on the bank layer and partitioning a light opening overlapping the plurality of light sensing portions and a touch electrode disposed on the first touch insulating pattern. A cross-sectional shape of the first touch insulating pattern has a reverse tapered shape having a width that decreases towards a top surface of the substrate.