Finger Vein Sensor Layout for Larger, Clearer Pattern Capture
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Solution Overview
Problem
Conventional finger vein sensors capture only a small portion of the finger vein pattern due to a small sensing surface, are prone to authentication errors from contamination, and fail with moisture on the sensor surface, limiting their use to indoor applications.
Innovation Solution
The finger vein sensor design includes an infrared light source positioned at the bottom, an image sensor at the top, and an optical reflector to capture larger and clearer finger vein patterns, with a transparent resting surface and infrared filter to prevent contamination and moisture interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensing surface area is increased to capture more finger vein pattern, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The patent extends the sensing surface in the horizontal plane rather than increasing vertical depth, allowing larger capture area without proportionally increasing overall device volume. The sensor array is arranged in a planar configuration that matches the natural placement of fingers on a flat surface.
Solution Approach 2:
The sensing surface is divided into multiple independent sensing elements arranged in an array. Each element captures a portion of the finger vein pattern, and the combined data from all elements provides comprehensive coverage. This segmentation allows the large sensing area to be constructed from manageable modular components.
2Reliability
If the sensing surface is made larger to reduce contamination impact, then the reliability is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The sensor is constructed from multiple discrete sensing elements that can be manufactured separately with standard precision tolerances and then assembled into a larger array. This modular approach reduces the cumulative precision requirements compared to manufacturing a single large integrated sensor.
Solution Approach 2:
The sensor design incorporates universal mounting structures and standardized element configurations that can be replicated across the array. This universality simplifies the assembly process and reduces the precision requirements for individual components, as each element follows the same design template.
3Reliability
If the sensor space is sealed to prevent moisture damage, then the reliability is improved, but the ease of operation deteriorates
Solution Approach 1:
The sensor employs a transparent protective cover that acts as a barrier to moisture while maintaining optical transparency for infrared transmission. This thin film structure protects the internal electronics from water damage without creating a physical barrier that would interfere with finger placement or vein pattern transmission.
4Measurement precision
If the sensing surface is made larger to capture more vein pattern, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The patent combines the light source and sensor array into a single integrated module, eliminating the need for separate optical paths and reducing overall system complexity. The infrared LEDs are positioned directly adjacent to the sensing elements, creating a compact configuration that simplifies alignment and reduces the number of optical components required.
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 design captures larger and clearer finger vein patterns, reducing authentication errors and enabling outdoor use by preventing contamination and moisture-related failures.
Implementation Method 1
an infrared light-emitting diode (LED) 409 irradiates infrared light on a finger 407
Implementation Method 2
an image sensor 1006 captures at least one infrared image of finger vein pattern
Implementation Method 3
an optical reflector to capture larger and clearer finger vein patterns
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
The present disclosure relates to several types of finger vein sensor. In certain embodiments, the finger vein sensor includes: an image sensor, and an infrared light source. Image sensor captures infrared image of finger vein pattern of a finger of a target human. The image sensor faces down and is positioned at top of finger vein sensor. The infrared light source may include a predetermined number of infrared light-emitting diodes (LED), and they are arranged in one or more rows and one or more columns and positioned at bottom of finger vein sensor. The finger is positioned between infrared light source and image sensor. The infrared light from the infrared light source irradiates the finger vertically from the bottom to generate the infrared image of finger vein pattern of the finger on the image sensor, and the image sensor captures the infrared image of finger vein pattern of the finger.