Optimizing Display Module Aperture Geometry for Fingerprint Recognition
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Solution Overview
Problem
Existing fingerprint recognition technologies using OLED display panels face issues with uneven light distribution due to the pinhole imaging principle, especially as screen thickness decreases, affecting recognition accuracy and sensitivity.
Innovation Solution
A display module with a fingerprint recognition layer, a display panel, and a cover plate, where the display panel includes a functional layer with fingerprint recognition light sources and imaging apertures, optimizing the distance between these components to ensure uniform light distribution and improve recognition performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the object distance is decreased to achieve thinner and lighter screens, then the screen thickness is reduced, but the light distribution becomes uneven and fingerprint recognition performance deteriorates
Solution Approach 1:
The patent changes the geometric parameters of the imaging system by optimizing the aperture diameter and adjusting the distances between the light source, aperture, and image sensor. Specifically, it sets the aperture diameter within 5-15μm and optimizes the distance relationships to satisfy specific ratio conditions, thereby improving light distribution uniformity while maintaining thin screen design
Solution Approach 2:
The patent transitions from traditional pinhole imaging to a more refined aperture imaging approach by carefully controlling the aperture diameter and spatial relationships in multiple dimensions. This dimensional optimization allows achieving both thin screen thickness and uniform light distribution for reliable fingerprint recognition
2Quantity of substance
If the aperture diameter is increased to improve light reception, then more light is received, but the imaging precision and light distribution uniformity deteriorate
Solution Approach 1:
The patent optimizes the aperture diameter parameter within a specific range (5-15μm) to achieve the best balance between light reception and imaging precision. This parameter optimization ensures sufficient light reaches the image sensor while maintaining sharp fingerprint image quality and uniform light distribution
3Device complexity
If the distance between light sources and sensors is not optimized, then the structure is simpler, but the photosensitivity uniformity and recognition accuracy worsen
Solution Approach 1:
The patent optimizes the distance parameters between the light source, aperture, and image sensor by establishing specific ratio relationships. This parameter optimization achieves uniform photosensitivity distribution across the sensor without requiring complex additional structural components
Solution Approach 2:
The patent creates equipotential conditions for light distribution by optimizing the spatial arrangement so that light reaches the image sensor uniformly across different regions. This is achieved by carefully controlling the distance ratios in the optical path to ensure consistent illumination conditions
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 optimized configuration enhances the uniformity of photosensitivity and improves fingerprint recognition performance by adjusting the distances between light sources and sensors, ensuring consistent light reception and accurate fingerprint detection.
Implementation Method 1
uses a small hole designed in the image sensors and the OLED display panel to realize the fingerprint recognition through the principle of the pinhole imaging
Implementation Method 2
the functional layer includes a plurality of fingerprint recognition light sources and a plurality of imaging apertures
Data Source
AI summary
A display module and a display device are provided. The display module includes a fingerprint recognition layer including photosensitive sensors, a display panel including a function layer containing fingerprint recognition light sources and imaging apertures, and a cover plate. A vertical distance between a surface of the cover plate at a side away from the functional layer and a corresponding imaging aperture is a first distance h1; a vertical distance between a photosensitive sensor and a corresponding imaging aperture is a second distance h2; along a direction parallel to a plane where the display panel is located, a distance between any two adjacent fingerprint recognition light sources is P1, and a distance between any two adjacent photosensitive sensors is P3;K=2P3×h1P1×h2;0.8N<K<1.2N; and N is a positive integer.