Under-screen Image Capture via Cover Plate Reflection
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Solution Overview
Problem
Current optical fingerprint recognition solutions for devices with increasing screen ratios face challenges such as complex structure, thick modules, small photosensitive range, and high costs, requiring larger sensors that occupy valuable space under the screen.
Innovation Solution
An image capturing device under the screen comprising a nonopaque cover plate, a light source module, and a photosensor module, where light from an array of light sources is totally reflected onto discrete photosensors, allowing for a larger imaging area without the need for a large sensor, thus reducing space occupation and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a larger sensor is disposed under the screen to obtain a larger imaging area, then the imaging area is improved, but the space occupation under the screen increases
Solution Approach 1:
The patent utilizes total internal reflection at the cover plate interface to redirect light from lateral regions into the sensor's active area. By changing the optical path dimensionality through reflection angles, the effective imaging area is expanded beyond the sensor's physical footprint, allowing a small sensor to capture a large imaging area without occupying more space under the screen.
Solution Approach 2:
The cover plate serves as an optical intermediary that redirects light from regions outside the sensor's direct projection area into the sensor. This intermediary component enables the sensor to receive light from a larger area without requiring the sensor itself to be larger or to occupy more space under the screen.
2Reliability
If traditional optical fingerprint recognition with lens is used, then imaging function is achieved, but the structure becomes complex and module thickness increases
Solution Approach 1:
The patent extracts and removes the lens component from the optical system, relying instead on total internal reflection at the cover plate interface to achieve the necessary light focusing and imaging. This extraction of the lens simplifies the overall structure, reduces module thickness, and eliminates the complexity associated with lens alignment and design while maintaining imaging functionality.
Solution Approach 2:
The patent replaces the mechanical lens-based optical system with a reflection-based optical system utilizing the cover plate interface. This substitution eliminates the need for complex mechanical lens assemblies and replaces them with a simpler reflection-based mechanism that achieves the same imaging function with reduced complexity and thickness.
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 configuration enables biometric information capture beyond the projection range of traditional sensors, reducing the required sensor area and hardware costs, while maintaining effective imaging performance.
Implementation Method 1
The light emitted from each light source toward the nonopaque area is reflected by the nonopaque cover plate and received by one photosensor in the photosensor module
Data Source
AI summary
The image capturing device under the screen and the electronic equipment including a nonopaque cover plate, a light source module, and a photosensor module are provided. The nonopaque cover plate, the light source module, and the photosensor module are sequentially arranged from top to bottom. The nonopaque cover plate is provided with nonopaque area, the light source module includes a plurality of light sources arranged in an array, the photosensor module comprises a plurality of discrete photosensors. The light emitted from each light source toward the nonopaque area is reflected by the nonopaque cover plate and received by one photosensor in the photosensor module. By the above-mentioned scheme, the biometric information on the nonopaque area that is outside the projection range of the photoelectric sensor can also be obtained by the photosensors, effectively increasing the imaging area of the photosensors, effectively reducing the area of the photosensors required to detect the same image information, preventing from occupying too much space under the screen, and saving hardware costs.