Biometric Image Pickup Transmittance Filter for Light Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Biometric image pickup systems face issues with uneven light distribution due to transmittance variations through living organisms, requiring complex light source adjustment mechanisms to achieve consistent image quality.
Innovation Solution
A biometric image pickup apparatus with a transmittance distribution filter arranged between the detection section and the image pickup device, where transmittance is higher in regions far from the light source than near it, reducing light variations without the need for complex light source adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light sources are arranged on both sides of the finger to illuminate the inside, then image pickup data of veins can be obtained, but light amount distribution in the image becomes uneven due to transmittance variations through the finger
Solution Approach 1:
The patent applies local quality by positioning light sources at specific locations (both sides of the finger) to create targeted illumination zones. Different regions of the finger receive different light intensities based on their distance from the light sources, with the filter compensating for this non-uniform distribution to achieve consistent image quality across the entire field of view.
Solution Approach 2:
The patent changes the optical parameters by introducing a transmittance filter with specific optical properties. The filter has higher transmittance in regions receiving less light and lower transmittance in regions receiving more light, thereby equalizing the overall light distribution. This parameter modification transforms the non-uniform light field into a uniform one without requiring mechanical adjustment mechanisms.
2Illumination intensity
If multiple light sources are arranged with computing sections to adjust light amounts, then light amount distribution can be controlled, but the system becomes complicated with additional adjustment mechanisms
Solution Approach 1:
The patent introduces a transmittance filter as an intermediary element between the light sources and the finger. This filter passively equalizes the light distribution by having spatially varying transmittance properties, eliminating the need for active control mechanisms, computing sections, or complex adjustment systems. The filter acts as a static mediator that automatically compensates for light distribution non-uniformity.
Solution Approach 2:
The patent replaces complex mechanical or electronic light adjustment mechanisms with a static optical filter. Instead of using movable parts, adjustable lenses, or electronic control systems to equalize light distribution, the invention uses a fixed filter with predetermined transmittance characteristics, thereby substituting a complex mechanical/electronic system with a simple optical component.
3Illumination intensity
If a transmittance distribution filter is arranged between the detection section and image pickup device, then light amount variations are reduced, but the device structure becomes more complex
Solution Approach 1:
The patent merges the transmittance filter with existing optical components in the system, such as integrating it into the lens assembly or detector housing. By combining the filter function with structural elements that already exist in the optical path, the patent minimizes additional complexity while achieving light distribution equalization. The filter becomes part of the integrated optical system rather than a separate additive component.
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 simplifies the system by reducing light variations in the picked-up image, eliminating the need for complicated light source adjustments, and enhances image quality by ensuring consistent light distribution across the image pickup region.
Implementation Method 1
a transmittance distribution filter arranged between the detection section and the image pickup device, in which the transmittance distribution filter has a transmittance distribution in which the transmittance is higher in a region far from the light source than in a region near the light source
Implementation Method 2
an image pickup lens section condensing light from the living organism
Data Source
AI summary
A biometric image pickup apparatus with a simple configuration capable of reducing light amount variations in a picked-up image. The biometric image pickup apparatus includes: a light source applying light to a living organism; a detection section for placing the living organism thereon; an image pickup lens section condensing light from the living organism; an image pickup device obtaining image pickup data on the basis of the light condensed by the image pickup lens section; and a transmittance distribution filter arranged between the detection section and the image pickup device, in which the transmittance distribution filter has a transmittance distribution in which the transmittance is higher in a region far from the light source than in a region near the light source.