Finger Biometric Sensor Stability Detection Circuitry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Touch-based finger biometric sensors often fail or take a long time to acquire data if the finger is not stationary or stable during data acquisition, leading to inefficiencies and inaccuracies.
Innovation Solution
The integration of an array of finger biometric sensing pixels with processing circuitry that determines finger stability through frequency-based detection and acquisition of stability data from a subset of sub-arrays arranged in a checkerboard pattern, allowing for accurate data acquisition only when the finger is stable relative to the sensor array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If touch-based finger biometric sensor is used for data acquisition, then personal identification capability is provided, but acquisition time increases and reliability decreases when finger is not stationary
Solution Approach 1:
The system performs preliminary finger stability detection before initiating full biometric data acquisition. The processing circuitry determines whether the finger is stable relative to the sensor array using a subset of sensing pixels, and only proceeds with acquisition when stability is confirmed, thereby preventing re-acquisitions and reducing total time
Solution Approach 2:
The system continuously monitors finger stability during the acquisition process and uses this feedback to determine whether to proceed with or abort the acquisition. The processing circuitry compares stability metrics against thresholds and adjusts acquisition decisions accordingly, improving reliability by avoiding acquisitions during motion
2Measurement precision
If finger stability detection is performed using full array of sensing pixels, then measurement precision is improved, but device complexity and processing load increase
Solution Approach 1:
The sensing pixel array is divided into multiple sub-arrays, and only a subset of these sub-arrays is actively used for stability detection at any given time. This segmentation allows the system to achieve sufficient measurement precision with fewer active pixels, reducing processing complexity while maintaining detection accuracy
Solution Approach 2:
The system uses a partial subset of the full sensing pixel array for stability detection rather than all pixels. This partial action is sufficient to determine finger stability without requiring the computational resources needed to process the entire array, thus reducing device complexity while maintaining measurement precision
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 approach reduces acquisition time and enhances the accuracy of finger biometric data by ensuring the finger is stationary before data collection, thereby improving the reliability and efficiency of the biometric sensing process.
Implementation Method 1
The fingerprint sensor is an integrated circuit sensor that drives the user's finger with an electric field signal and senses the electric field with an array of electric field sensing pixels on the integrated circuit substrate
Implementation Method 2
The processing circuitry may be capable of determining whether the finger is adjacent the array of finger biometric sensing pixels based upon a change in an oscillation frequency associated with the array of finger biometric sensing pixels
Data Source
AI summary
A finger biometric sensor may include an array of finger biometric sensing pixels and processing circuitry coupled to the array of finger biometric sensing pixels. The processing circuitry may be capable of acquiring finger stability biometric data from a subset of the array, and determining whether a finger is stable relative to the array of finger biometric sensing pixels based upon the finger stability biometric data. The processing circuitry may also be capable of acquiring finger biometric data from the array of finger biometric sensing pixels when the finger is stable.