Biometric Display Photo Sensor Stack for High-Resolution Sensing
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Solution Overview
Problem
Existing display devices with biometric sensors face challenges in achieving improved sensing sensitivity and high resolution, particularly in integrating biometric sensors with display panels effectively.
Innovation Solution
The display device incorporates a pixel and a photo sensor with specific transistor configurations, including a silicon semiconductor and an oxide semiconductor, where the transistors are disposed in different layers with insulating layers in between, and share scan lines to facilitate simultaneous scanning and threshold voltage compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a biometric sensor is integrated with a display panel, then sensing sensitivity and resolution are improved, but device complexity increases due to multiple transistor layers and material integration
Solution Approach 1:
The photo sensor is segmented into multiple transistor components (first sensor transistor, second sensor transistor, third sensor transistor) with distinct functions, where each transistor is formed in separate layers using different semiconductor materials. This segmentation allows optimized performance for each component while managing overall complexity through functional division.
Solution Approach 2:
The patent employs composite material structure by integrating first type semiconductor (e.g., silicon) and second type semiconductor (e.g., oxide semiconductor) in different transistor layers. This composite approach combines the high mobility advantages of silicon with the low leakage current benefits of oxide semiconductors, achieving enhanced sensing sensitivity and resolution.
2Measurement precision
If multiple transistors with different semiconductor types are used in the photo sensor, then sensing performance is enhanced, but manufacturing precision requirements increase due to multi-layer integration
Solution Approach 1:
The patent transitions from planar integration to three-dimensional layered integration, with semiconductor layers disposed at different vertical levels separated by insulating layers. This dimensional approach allows multiple transistor types to coexist without direct lateral interference, reducing manufacturing precision requirements while achieving high resolution through the stacked configuration.
Solution Approach 2:
Insulating layers are introduced as intermediary elements between the first type semiconductor layer and second type semiconductor layer. These intermediary insulating layers provide electrical isolation and mechanical decoupling, reducing the precision requirements for direct interface alignment between different semiconductor materials while maintaining signal integrity.
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 configuration enhances sensing sensitivity and resolution, enabling efficient biometric authentication, such as fingerprint sensing, by optimizing the operation of both pixel and photo sensor components.
Implementation Method 1
a light receiving element; a first sensor transistor configured to control current flowing to a readout line in response to a voltage of one electrode of the light receiving element
Data Source
AI summary
A display device may include photo sensors connected to a readout line. Each of the photo sensors may include: a light receiving element; a first sensor transistor configured to control current flowing to the readout line in response to a voltage of one electrode of the light receiving element; and a second sensor transistor electrically connected between the first sensor transistor and the readout line. The first sensor transistor may include a silicon semiconductor. The second sensor transistor may include an oxide semiconductor.