In-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 a 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
1Reliability
If a photosensing-type fingerprint sensor is used to provide fingerprint sensing function, then the fingerprint sensing capability is enabled, but the sensor can recognize fake fingerprints made of various materials leading to unauthorized device use
Solution Approach 1:
The fingerprint area is divided into multiple distinct areas (first area with first light-emitting element, second area with second light-emitting element, third area with third light-emitting element). Each area independently emits light and is sensed by corresponding photosensors to generate separate images (fingerprint authentication image and fake verification image), enabling multi-zone analysis to detect fake fingerprints
Solution Approach 2:
Different areas of the fingerprint sensor have different light-emitting characteristics and sensing functions. The first area is optimized for fingerprint authentication while the second area specifically targets fake fingerprint detection by analyzing light reflection patterns that differ between real and fake fingerprints
2Reliability
If multiple light-emitting elements and photosensors are arranged in different areas to generate authentication and verification images, then fake fingerprint detection capability is improved, but the device complexity increases
Solution Approach 1:
The fingerprint authentication function and fake fingerprint verification function are merged into a single integrated sensor layer structure. Both functions share the same substrate, light-emitting element layer, and sensor layer, with only the arrangement and control of light-emitting elements and photosensors differing, thereby reducing overall system complexity compared to separate authentication and verification devices
Solution Approach 2:
The sensor layer serves multiple functions: it detects light from the first light-emitting element for fingerprint authentication, detects light from the second light-emitting element for fake verification, and can potentially detect light from other areas. This multi-functional design eliminates the need for separate authentication and verification sensor systems
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
Effectively differentiates between real and fake fingerprints, enhancing security by reducing the likelihood of unauthorized access without the need for additional verification devices, while maintaining manufacturing cost efficiency.
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.