Finger Vein Authentication Device with Segmented Imaging
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Solution Overview
Problem
Existing finger vein authentication devices with narrow imaging ranges face issues such as incorrect user identification due to finger deviation and potential damage to blood vessel patterns from strong finger pressing, as well as adverse effects from nearby fingers blocking or reflecting light, leading to reduced authentication accuracy.
Innovation Solution
A finger vein authentication device with a compact design that includes a center finger stand, left and right finger stands made of light-blocking material, and an adjustable light source configuration to stabilize the finger and prevent interference from adjacent fingers, ensuring accurate image capture and enhanced authentication accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a narrow imaging range is used to make the device compact, then device size is reduced, but finger positioning stability deteriorates and authentication accuracy decreases
Solution Approach 1:
The imaging field is segmented into multiple regions using light blocking members that divide the imaging range into a first imaging range (for the authentication finger) and a second imaging range (for adjacent fingers). This segmentation allows the device to maintain a compact form factor while improving finger positioning stability by providing distinct imaging zones that reduce interference between fingers.
Solution Approach 2:
Different regions of the imaging field are assigned different functions: the first imaging range is optimized for capturing vein patterns of the authentication finger with high quality, while the second imaging range is used to monitor and exclude adjacent fingers. This local differentiation of imaging quality and function resolves the contradiction between compact size and authentication reliability.
2Measurement precision
If light is irradiated from the left and right sides to capture finger veins, then vein image capture is improved, but adjacent fingers block or reflect light causing authentication errors
Solution Approach 1:
The light irradiation system is segmented into multiple light sources positioned at different locations (left side, right side, and bottom). Light blocking members are strategically placed to direct light from each source to specific regions: light from the left and right sources illuminates the authentication finger for vein capture, while light from the bottom source illuminates adjacent fingers. This segmentation prevents light blocking and reflection issues while maintaining high vein image quality.
Solution Approach 2:
Light blocking members act as intermediaries that control and direct light paths between light sources and fingers. These members prevent light from adjacent fingers from blocking or reflecting into the imaging path of the authentication finger, thereby eliminating authentication errors while preserving high-quality vein image capture.
3Device complexity
If the imaging range is narrowed to improve device compactness, then device complexity is reduced, but finger positioning stability and authentication reliability worsen
Solution Approach 1:
The device structure is segmented into functional modules: light sources positioned at left, right, and bottom; light blocking members arranged to create distinct imaging ranges; and an imaging device with specific optical path control. This segmentation achieves compactness by efficiently arranging components while improving authentication reliability through controlled light paths and separate imaging zones for the authentication finger and adjacent fingers.
Solution Approach 2:
The light blocking members serve multiple functions: they divide the imaging field into distinct ranges, control light paths from multiple light sources, prevent light blocking and reflection from adjacent fingers, and stabilize finger positioning. This multi-functionality reduces the need for additional components, maintaining device compactness while significantly improving authentication reliability.
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 device achieves high reproducibility and accuracy by stabilizing the finger and preventing adverse effects from nearby fingers, resulting in improved image quality and authentication reliability.
Implementation Method 1
The hemoglobin in the blood fluid at this time absorbs the infrared light more than the surrounding tissue
Data Source
AI summary
An authentication device including: a finger presenting unit to which a finger to be authenticated is presented; an opening formed on the finger presenting unit; a light source that irradiates light onto the finger; an image capture unit that captures a picture including a vein of the finger, by the light; and a finger placement table capable of placing a finger thereon, except the finger to be authenticated, wherein the finger placement table has a surface, a height of which is higher than the finger presenting unit, wherein the light source is placed inside the finger placement table, and wherein the finger placement table has a sidewall having a window that is used to allow an irradiation axis of the light from the light source upon the image capture unit.