Color Filter Pixel Array for Fake Fingerprint Detection
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Solution Overview
Problem
Existing optical fingerprint technologies face challenges in authenticating fingerprints, as artificial materials like silica gel can mimic real fingerprints, compromising security.
Innovation Solution
The implementation of a fingerprint identification apparatus with filter units in at least two colors above pixel units captures low-resolution color fingerprint images, distinguishing between real and artificial fingerprints based on significant differences in image characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional optical fingerprint sensing is used, then fingerprint capture is simple and fast, but security is compromised due to ability to detect fake fingerprints
Solution Approach 1:
The sensor is divided into multiple pixel units, each equipped with its own filter unit. This segmentation allows independent optical filtering at each pixel level, enabling color fingerprint imaging without requiring a completely complex multi-sensor system. Each pixel unit processes information independently, maintaining simplicity while enhancing security through color differentiation capability.
Solution Approach 2:
Different filter units with different color characteristics are assigned to different pixel units. This local quality differentiation enables the system to capture color information specific to each region, allowing distinction between real and fake fingerprints through color analysis without requiring uniform complex processing across the entire sensor.
2Measurement precision
If color fingerprint imaging is implemented using multiple filters, then authentication accuracy improves, but image resolution decreases
Solution Approach 1:
Instead of using multiple separate sensors or complex multi-filter systems that would fully capture color information, the patent applies partial action by using filter units at selected pixel units. This partial implementation provides sufficient color differentiation for security purposes while avoiding the complete resolution loss that would occur with full-color imaging systems, achieving a balance between accuracy and resolution.
Solution Approach 2:
The system uses color filter units that transmit different wavelengths of light to create color fingerprints. By analyzing color characteristics (red, green, blue channel responses) from the fingerprint image, the system achieves high authentication accuracy through color-based differentiation between real and fake fingerprints, compensating for the reduced spatial resolution.
3Measurement precision
If multiple fingerprint images are captured for comparison, then identification accuracy increases, but detection time increases
Solution Approach 1:
The filter units are pre-configured with different color characteristics before the fingerprint capture process. This preliminary setup enables the system to simultaneously capture multiple wavelength information in a single image capture operation, eliminating the need for sequential multi-image capture and comparison, thus reducing authentication time while maintaining accuracy.
Solution Approach 2:
The patent merges multiple filtering operations into a single capture process by having multiple filter units work simultaneously on different pixel units. Instead of capturing multiple separate images and then comparing them, the system combines color information from different wavelengths in one unified fingerprint image, achieving both accuracy and speed.
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 approach enhances fingerprint authentication security by allowing a single capture to produce color fingerprint images, improving efficiency and accuracy in differentiating between real and fake fingerprints.
Implementation Method 1
at least two filter units disposed above at least two of the plurality of pixel units, each filter unit corresponding to one pixel unit, and the at least two filter units including filter units in at least two colors
Data Source
Figure 1~2
Figure 3
Figure 4~5(i)
AI summary
Provided are a fingerprint identification apparatus and an electronic device. The fingerprint identification apparatus includes: a micro lens array; at least one light shielding layer; a pixel unit array; and an array of filter unit groups, where each filter unit group in the array of filter unit groups includes at least two filter units, and the at least two filter units are configured to transmit light signals in at least two colors respectively, where the pixel unit array includes a pixel unit group corresponding to the filter unit group, at least two pixel units in the pixel unit group receive a first light signal through the at least two filter units respectively, and a pixel unit except the at least two pixel units in the pixel unit group receives a second light signal through a transparent region between the at least two filter units, or a pixel unit between pixel unit groups receives the second light signal through a transparent region between the filter unit groups. The fingerprint identification apparatus can improve the security of fingerprint identification without affecting the fingerprint identification effect.