Under-screen Fingerprint Recognition via Total Internal Reflection
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Solution Overview
Problem
Conventional display panels and electronic devices face the challenge of limited portability in fingerprint recognition, as existing methods, such as capacitive and optical fingerprint recognition, are typically fixed in a small area, affecting the aesthetic and usability of devices with increasing screen-to-body ratios.
Innovation Solution
A display panel design incorporating a protective layer, a light source module, and a light sensor, where the light source module emits light that enters the protective layer at a critical angle, allowing for total reflection and enabling under-screen fingerprint recognition by reflecting light from a user's finger to the sensor, thus expanding the recognition area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a single-point fingerprint recognition method is used, then the device structure is simple, but the recognition area is limited to a specific small area
Solution Approach 1:
The patent transitions from single-point fingerprint recognition to full-screen fingerprint recognition by utilizing the display screen surface as the recognition area. The light source module emits light through the protective layer and display screen, and the light sensor detects reflected light from the fingerprint sensor beneath the display, enabling fingerprint recognition across the entire screen area rather than at a single fixed point.
2Area of stationary object
If capacitive fingerprint recognition is used, then the recognition function is reliable, but the aesthetic is destroyed and no space is available with increasing screen-to-body ratio
Solution Approach 1:
The patent merges the fingerprint recognition function with the display screen by integrating the light source module, protective layer, display screen, and light sensor into a unified structure. The fingerprint recognition system is combined with the existing display components, allowing the screen to serve dual purposes: displaying information and enabling fingerprint recognition across its entire surface.
3Shape
If optical fingerprint recognition is used, then the aesthetic is maintained, but the recognition area is fixed in a small area
Solution Approach 1:
The patent makes the display screen universal by enabling it to perform both display functions and fingerprint recognition functions across its entire surface. The light source module and light sensor are positioned to illuminate and detect light from the entire screen area, allowing any portion of the screen to serve as a fingerprint recognition zone, thus providing multi-functionality while maintaining aesthetic appeal.
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 solution enhances the range and convenience of fingerprint recognition by allowing it to be performed across the display area, rather than being limited to a specific small area, improving the user experience and device aesthetics.
Implementation Method 1
outgoing light emitted by the light source module enters the protective layer in a first direction, and in a cross sectional viewing angle, an angle between the first direction and a thickness direction of the protective layer is greater than a critical angle of the outgoing light on a light emitting surface of the protective layer
Data Source
AI summary
A display panel and an electronic device are provided. The electronic device includes the display panel. The display panel includes a display panel main body, a protective layer, a light source module, and a light sensor. Outgoing light emitted by the light source module can be totally reflected in the protective layer. When a finger touches an area of the protective layer corresponding to a display area, light emitted to the finger can be reflected to light sensor. As such, a range of under-screen fingerprint recognition can be increased.