Coded Aperture Mask for Fingerprint Recognition
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Solution Overview
Problem
Existing optical fingerprint recognition technologies face interference from ambient light and require high resolution and sensor density, leading to fuzzy or unrecognizable fingerprint images due to the inclusion of non-texture carrying light.
Innovation Solution
A display panel incorporating a coded aperture mask layer and optical sensing layer, which forms a coded aperture array to filter out non-texture carrying light, converting texture recognition light into electrical signals and restoring a clear texture image using image restoration algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical sensors are used to capture fingerprint images, then fingerprint recognition can be implemented, but ambient light interference causes fuzzy or unrecognizable images
Solution Approach 1:
A coded aperture mask is introduced as an intermediary component between the ambient light source and the optical sensors. This mask modulates the ambient light into a coded pattern before it reaches the sensors, allowing the system to distinguish between ambient light and reflected fingerprint light through computational algorithms, thereby eliminating ambient light interference while maintaining recognition accuracy
Solution Approach 2:
The solution combines optical hardware (coded aperture mask with specific transmission patterns) and computational software (image restoration algorithms) to create a composite recognition system. This hybrid approach allows the system to process coded light patterns and reconstruct clear fingerprint images even in the presence of ambient light, resolving the contradiction between optical sensing capability and ambient light sensitivity
2Manufacturing precision
If high resolution and sensor density are used to improve image quality, then clearer fingerprint images can be obtained, but manufacturing complexity and cost increase
Solution Approach 1:
Instead of using high-density optical sensors to directly capture clear images, the system uses a coded aperture mask to create a coded copy of the light field. Lower-density sensors capture this coded pattern, and computational algorithms reconstruct the clear fingerprint image from the coded data, achieving high image quality without requiring high sensor density
Solution Approach 2:
The system changes the spatial distribution parameter of light transmission through the coded aperture mask, creating a specific coded pattern that encodes spatial information. This parameter transformation allows the reconstruction of high-resolution images from lower-density sensor data through computational processing, avoiding the need for high sensor density
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 enhances the accuracy of texture recognition, reducing the need for high pixel density and simplifying the manufacturing process, resulting in clear and accurate texture images without the interference of ambient light.
Implementation Method 1
the optical sensing layer is configured to receive texture recognition light passed through the coded aperture array and convert optical signals of the texture recognition light into electrical signals
Data Source
AI summary
A display panel has a light-exit side and a non-light-exit side opposite to the light-exit side. A direction pointing to the non-light-exit side from the light-exit side is a first direction. In the first direction, the display panel includes a coded aperture mask layer and an optical sensing layer. The coded aperture mask layer includes a plurality of first light-transmission portions and a plurality of first light-shielding portions. The coded aperture mask layer is configured to form at least one part of a coded aperture array. The optical sensing layer includes a plurality of optical sensors. The optical sensing layer is configured to receive texture recognition light passed through the coded aperture array and convert optical signals of the texture recognition light into electrical signals. The texture recognition light is light carrying information about a texture to be recognized.