Photodiode Opening Layout to Reduce Display Moiré
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Solution Overview
Problem
Existing detection devices face challenges in reducing moiré patterns caused by the arrangement of photodiodes and sub-pixels in display devices, which affects the accuracy of light detection and fingerprint recognition.
Innovation Solution
A detection device is designed with a substrate having photodiodes arranged in a specific direction, overlapped by lenses, and a light-blocking layer with multiple openings of varying diameters and orientations, which helps in blocking oblique light components and reducing crosstalk, thereby minimizing moiré patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the arrangement direction of photosensors is aligned with the arrangement direction of display device pixels, then the manufacturing and assembly process is simplified, but moiré patterns occur in the incident light
Solution Approach 1:
The patent applies asymmetry by arranging the openings in the light-blocking layer at an angle different from the arrangement direction of the photodiodes. Specifically, while photodiodes are arranged in a first direction, the openings are arranged in a second direction that forms an angle with the first direction. This asymmetric arrangement breaks the periodicity that causes moiré patterns, allowing both simplified manufacturing and elimination of interference fringes.
2Reliability
If multiple openings are provided in each region overlapping photodiodes, then light blocking effectiveness is improved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the light-blocking function into multiple separate openings within each region overlapping a photodiode. Instead of using a single large light-blocking structure, multiple smaller openings are provided, each contributing to the overall light blocking effectiveness. This segmented approach enhances reliability by providing redundant light blocking paths while maintaining manageable structural complexity through the systematic arrangement of these segmented elements.
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 solution effectively reduces moiré patterns and improves detection accuracy by ensuring that light is focused correctly on the photodiodes, enhancing the detection of fingerprints and other living body information.
Implementation Method 1
a plurality of lenses provided so as to overlap the photodiodes
Implementation Method 2
a light-blocking layer provided between the photodiodes and the lenses and having a plurality of openings
Implementation Method 3
a plurality of photodiodes provided to the substrate and arranged in a first direction
Data Source
AI summary
According to an aspect, a detection device includes: a substrate; a plurality of photodiodes provided to the substrate and arranged in a first direction; a plurality of lenses provided so as to overlap the photodiodes; and a light-blocking layer provided between the photodiodes and the lenses and having a plurality of openings. More than one of the openings is provided in each of regions overlapping the respective photodiodes, and an arrangement direction of the openings in each of the regions overlapping the respective photodiodes is at an angle to the first direction.