Sensor Assembly Illumination for Biometric Hand Imaging
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Solution Overview
Problem
Traditional biometric identification systems using palm-based imaging face issues with low-quality images due to irregular hand shapes, resulting from over- and under-illumination, leading to glare and darkened areas that hinder feature recognition.
Innovation Solution
A sensor assembly with strategically positioned light modules, including a first and second light module with varying intensities and polarizations, and light bending films that redirect light away from the center of the field of view towards the edges, providing even illumination and reducing glare, while diffusers spread light to enhance image quality without requiring physical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If traditional uniform illumination is used to illuminate the hand, then the illumination intensity is sufficient, but over-illuminated and under-illuminated regions occur due to irregular hand shape
Solution Approach 1:
The patent applies local quality by varying the illumination intensity across different regions of the hand. Light modules are positioned and configured to provide different intensities to different areas - higher intensity to under-illuminated regions and lower intensity to over-illuminated regions - thereby achieving uniform illumination across the irregular hand surface
Solution Approach 2:
The illumination system is segmented into multiple light modules (first light module, second light module, third light module) that can be independently controlled. Each light module illuminates specific regions of the hand, allowing precise control over illumination distribution to eliminate over and under-illuminated areas
2Use of energy by moving object
If direct light is used to illuminate the hand, then illumination efficiency is high, but glare and darkened areas occur that hinder feature recognition
Solution Approach 1:
The patent introduces light bending films as intermediary elements between the light modules and the hand. These films redirect light paths to eliminate direct glare-causing reflections while maintaining illumination efficiency, thereby preventing information loss in the form of glare and darkened areas
Solution Approach 2:
The patent changes the illumination parameters by using light bending films to alter light direction and diffusers to modify light distribution. This transforms direct, harsh illumination into diffused, evenly distributed illumination that maintains efficiency while eliminating glare
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 achieves improved image quality by minimizing glare and dark regions, enabling accurate user identification through even illumination and enhanced visualization of both surface and internal hand features without physical contact.
Implementation Method 1
A sensor assembly with strategically positioned light modules, including a first and second light module with varying intensities and polarizations
Implementation Method 2
light bending films that redirect light away from the center of the field of view towards the edges
Implementation Method 3
while diffusers spread light to enhance image quality without requiring physical contact
Data Source
AI summary
A device for providing even illumination to a user’s hand or other object to acquire images of the object for biometric identification of a user, includes a camera, a first light module positioned on a first side of the camera, and a second light module positioned on a second side of the camera. The camera is positioned closer to the second light module. The second light module emits light with a lesser intensity than the first light module. Light bending films positioned adjacent to the light modules redirect emitted light toward opposite edges of the field of view of the camera. Diffusers in the path of the emitted light diffuse portions of the emitted light along the edges of the field of view. Polarizers positioned in the path of the emitted light polarize the emitted light to facilitate visualization of particular features of the hand or other object.