Miniaturized Optical Biometric Sensor Using Subsurface Tissue Analysis
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Solution Overview
Problem
Traditional biometric detection systems are too large and expensive for miniaturized applications, and they have limited reliability across varying operating conditions such as skin wetness or dryness and ambient lighting, as well as difficulty in distinguishing between genuine skin and spoofing attempts.
Innovation Solution
A miniaturized optical biometric sensor system with multiple light sources illuminating skin at multiple locations, using an imaging array to capture images of light that has interacted with subsurface tissue characteristics, enabling reliable biometric functions like identity verification and access control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional optical biometric approaches are used, then biometric detection function is achieved, but device size becomes too large for miniaturized applications
Solution Approach 1:
The sensor is divided into distinct functional zones: illumination regions that emit light into the tissue and a separate imaging region that captures light exiting the tissue. This segmentation allows each zone to be optimized independently, enabling miniaturization while maintaining detection reliability through specialized functionality in each segment.
Solution Approach 2:
The patent transitions from surface-level light reflection detection to subsurface light interaction detection by having illumination pass through the tissue and capture light exiting from different regions. This dimensional shift into subsurface interaction enables more reliable biometric detection in a compact form factor by exploiting depth information rather than just surface characteristics.
2Volume of moving object
If smaller and less expensive sensors are used, then device cost and size are reduced, but reliability across varying operating conditions deteriorates
Solution Approach 1:
Different regions of the sensor are assigned different qualities and functions: illumination regions are optimized for light emission while the imaging region is optimized for light capture. This local differentiation allows the compact sensor to maintain high reliability across varying conditions by having specialized zones that compensate for environmental variations.
Solution Approach 2:
The sensor design integrates multiple functions within a compact structure: illumination sources, optical coupling elements, and imaging detection are combined in a single integrated sensor. This multi-functionality enables reliable biometric detection across diverse operating conditions while maintaining a small form factor suitable for mobile devices.
3Reliability
If traditional biometric sensors are used, then basic detection is achieved, but ability to distinguish between genuine skin and spoof deteriorates
Solution Approach 1:
The patent introduces optical coupling elements as intermediaries between the illumination sources and the imaging detector. These intermediaries manipulate light paths to ensure that only light that has interacted with subsurface tissue characteristics reaches the detector, providing a reliable mechanism for distinguishing genuine skin from spoofs without excessive structural complexity.
Solution Approach 2:
The patent replaces complex mechanical spoof detection mechanisms with optical field-based detection. By analyzing how light interacts with and exits the tissue at different regions, the system achieves genuine skin verification through optical characteristics rather than mechanical complexity, maintaining sensor compactness while improving anti-spoof 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 system provides reliable biometric access control in a compact form factor, effective across diverse conditions, and capable of distinguishing between genuine and spoofed biometric inputs, enhancing security and usability in various applications.
Implementation Method 1
an imaging array can be implemented to only receive light that has passed into and interacted with subsurface portions of the tissue. Some implementations use the images to perform biometric functions.
Implementation Method 2
the images can be used to identify an individual, verify identity of an individual, estimate demographic characteristics of an individual
Data Source
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AI summary
Systems and methods are described for providing reliable biometric access control using an optical biometric sensor in a miniaturized form factor. Some implementations include multiple light sources that can illuminate skin or other tissue at multiple locations during a single measurement session. An imaging array can be arranged to form images of the light exiting the tissue only after undergoing diffuse reflectance in the tissue. Some implementations use the images to perform biometric functions. For example, the images can be used to identify an individual, verify identity of an individual, estimate demographic characteristics of an individual, etc. Such biometric functions can further be used to determine and affect access to secured assets.