Biometric Sensor Scanning Light Source for Fingerprint Recognition
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Solution Overview
Problem
Silicon-based fingerprint sensors face challenges in scaling up for large-size screens due to increased costs and complex alignment processes required for collimated films, which limits production capacity and sensor thickness.
Innovation Solution
A biometric sensor design featuring a light emitting layer, touch detection layer, and photo-sensing layer on a base substrate, with a processor controlling a scanning light source to scan in linear patterns, eliminating the need for a collimating film by detecting light intensity distribution for fingerprint recognition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If collimated films are used in silicon-based fingerprint sensors for large-size screens, then fingerprint recognition accuracy is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent removes the collimated film component from the sensor structure entirely. Instead of using a collimated film to control light direction, the invention employs a light emitting layer integrated with the display structure that directly provides structured illumination for fingerprint detection, eliminating the need for separate collimation components and their complex alignment procedures
Solution Approach 2:
The light emitting layer serves multiple functions: it acts as both the display backlight source and the illumination source for fingerprint recognition. This multi-functional design integrates what were previously separate components (display system and biometric sensor), simplifying the overall structure and reducing manufacturing complexity while maintaining recognition accuracy
2Measurement precision
If collimated films are used in silicon-based fingerprint sensors, then light detection precision is improved, but sensor thickness increases
Solution Approach 1:
The patent combines the light emitting function and the display function into a single integrated structure. The light emitting layer is positioned within the display stack, and its emitted light is directly utilized for fingerprint illumination without requiring additional thick collimation layers, thereby reducing overall sensor thickness while preserving light detection precision
3Area of stationary object
If silicon-based sensors are scaled up for large-size screens, then coverage area is improved, but production cost increases
Solution Approach 1:
By making the light emitting layer serve dual purposes (display illumination and fingerprint scanning), the patent enables large-size screen coverage without proportionally increasing costs. The same light emitting structure covers the entire display area and simultaneously provides fingerprint recognition capability across the same area, avoiding the need for separate expensive large-area collimated film components
4Measurement precision
If collimated films are used in fingerprint sensors, then light reflection detection is improved, but production capacity decreases
Solution Approach 1:
The patent eliminates the collimated film component that requires complex alignment procedures during manufacturing. By using the light emitting layer integrated into the display structure, the invention removes the time-consuming alignment step, thereby increasing production capacity and manufacturing efficiency while maintaining sufficient light reflection detection capability for accurate fingerprint recognition
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
Enables efficient fingerprint recognition on larger screens without the need for collimating films, reducing sensor thickness and production complexity while maintaining recognition accuracy.
Implementation Method 1
a light emitting layer and a touch detection layer on the base substrate
Implementation Method 2
detect at least a portion of a light totally reflected by a surface of the biometric sensor
Implementation Method 3
a photo-sensing layer between the light emitting layer and the base substrate, and comprising a plurality of photosensors
Implementation Method 4
control the light emitting layer to form a scanning light source to scan the scanning region in a scanning pattern
Data Source
AI summary
A biometric sensor configured to detect a biometric information is provided. The biometric sensor includes a light emitting layer and a touch detection layer; an encapsulating cover on the light emitting layer; a photo-sensing layer configured to detect at least a portion of a light totally reflected by a surface of the biometric sensor in touch with a skin of a user; a touch sensing circuit configured to determine a touch position of a touch; a processor configured to determine a scanning region based on the touch position, and configured to control the light emitting layer to form a scanning light source to scan the scanning region in a scanning pattern; and a biometric information analysis circuit configured to determine a light intensity distribution of a reflected light reflected by the surface of the biometric sensor, and configured to determine the biometric information based on the light intensity distribution.