Display Fingerprint Sensor Layout for Fake Print Detection
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Solution Overview
Problem
Photosensing-type fingerprint sensors in display devices are vulnerable to recognizing fake fingerprints made of various materials, leading to potential unauthorized device use, as they cannot distinguish between real and fake biometric fingerprints effectively.
Innovation Solution
A display device with a fingerprint area containing a light-emitting element layer and a sensor layer, where the light-emitting elements in different areas emit or do not emit light to generate fingerprint and fake verification images, allowing the fingerprint detector to determine authenticity based on the average gray level of the fake verification image compared to a preset reference value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a photosensing-type fingerprint sensor is used, then the fingerprint sensing function is provided, but the sensor recognizes fake fingerprints made of various materials as real biometric fingerprints
Solution Approach 1:
The fingerprint sensor is divided into multiple sensing regions: a first sensing region with first photosensors for capturing fingerprint images, and a second sensing region with second photosensors for detecting light scattering characteristics. This segmentation allows the system to simultaneously perform authentication and liveness detection, distinguishing real fingerprints from fake ones by analyzing different optical properties in different regions.
Solution Approach 2:
The patent utilizes changes in light scattering parameters to differentiate between real and fake fingerprints. Real fingerprints exhibit specific light scattering characteristics due to their biological structure (ridges, valleys, sweat pores), while fake fingerprints made of materials like paper, rubber, or gelatin show different scattering patterns. By measuring and comparing these optical parameter variations, the system achieves accurate authentication.
2Measurement precision
If multiple light-emitting elements and photosensors are arranged in different areas, then the authentication accuracy is improved, but the device structure becomes more complex
Solution Approach 1:
The display device's pixel structure serves dual purposes: it functions as both the display and as the light source for fingerprint sensing. The pixels emit light that penetrates the fingerprint and reaches the photosensors, eliminating the need for separate light-emitting components. This multi-functionality reduces device complexity while maintaining authentication accuracy through the use of multiple sensing regions.
Solution Approach 2:
The patent merges the fingerprint sensing function with the display structure by integrating photosensors within or beneath the display panel. The display pixels and photosensors are combined in a single device architecture, where the display serves as both the interface and the illumination source. This integration reduces the number of separate components and simplifies the overall device structure.
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 differentiates between real and fake fingerprints, enhancing security by reducing the potential for unauthorized use without increasing manufacturing costs or fingerprint sensing time, and simultaneously acquiring fingerprint recognition and fake verification images.
Implementation Method 1
A light-emitting element layer is disposed on the substrate. The light-emitting element layer includes light-emitting elements.
Implementation Method 2
The photosensor may receive reflected light from a user's fingertip, and may then acquire corresponding fingerprint information.
Implementation Method 3
a light-blocking layer is interposed between the substrate and the light-emitting element layer. The light-blocking layer includes openings.
Data Source
AI summary
Provided is a display device including a substrate including a fingerprint area. The fingerprint area includes a first area and a second area. A light-emitting element layer is disposed on the substrate. The light-emitting element layer includes light-emitting elements. A sensor layer is disposed on the substrate, the sensor layer including photosensors. The light-emitting elements include a first light-emitting element arranged in the first area and a second light-emitting element arranged in the second area. During a fingerprint sensing period, the first light-emitting element emits light and the second light-emitting element does not emit light.