Optical Fingerprint Sensing Circuit With Signal Hold-and-Scan Readout
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Solution Overview
Problem
Optical fingerprint identification devices face challenges in collecting electrical signals from multiple fingerprint identification circuits within a short user finger residence time, affecting the accuracy and efficiency of fingerprint identification.
Innovation Solution
A fingerprint identification circuit comprising a light sensation circuit, a holding circuit, and a scanning circuit, where the light sensation circuit generates an electrical signal from detected light, the holding circuit stores potential information, and the scanning circuit amplifies and outputs a second electrical signal for fingerprint recognition, allowing for efficient signal collection even with a large number of circuits and short finger residence time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large number of fingerprint identification circuits are set to improve fingerprint identification accuracy, then the measurement precision is improved, but the device complexity increases and the signal collection becomes more difficult within short residence time
Solution Approach 1:
The fingerprint identification device is divided into multiple independent fingerprint identification circuits arranged in an array, with each circuit independently detecting light signals from specific regions of the finger. This segmentation allows parallel signal collection from multiple circuits, improving both measurement precision through more data points and managing device complexity by using identical modular circuit units throughout the array.
2Measurement precision
If multiple fingerprint identification circuits are used to improve identification accuracy, then the measurement precision is improved, but the loss of time increases due to the need to collect signals from all circuits within short residence time
Solution Approach 1:
The holding circuit stores the electrical signals generated by the light sensation circuit before scanning and reading operations are performed. This preliminary storage action allows signals from all fingerprint identification circuits to be captured and held simultaneously during the short finger residence time, eliminating the need for rapid sequential collection and thus reducing time loss while maintaining high measurement precision.
3Measurement precision
If a large number of fingerprint identification circuits are arranged to improve identification accuracy, then the measurement precision is improved, but the productivity decreases due to inefficient signal collection from numerous circuits
Solution Approach 1:
Multiple fingerprint identification circuits are merged into a unified array structure with shared scanning and reading circuits. The light sensation circuits generate signals that are collectively held and then scanned through shared control circuits, allowing simultaneous signal collection from all circuits in the array. This merging approach maintains high measurement precision through multiple detection points while significantly improving productivity by eliminating redundant individual readout paths.
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
Improves the intensity and signal-to-noise ratio of output signals, enhancing the accuracy of fingerprint identification and supporting designs with higher density and larger area fingerprint identification circuits.
Implementation Method 1
the photosensitive device converts a light signal into an electrical signal
Data Source
AI summary
A fingerprint identification circuit, a display panel, and a control method thereof. A first electrical signal is generated by a light sensation circuit in that fingerprint identification circuit according to the detected optical signal reflected by the finger, potential information of the first electrical signal is stored in a holding circuit, and a second electrical signal for fingerprint identification is output by a scanning circuit according to the potential information of the first electrical signal stored in the holding circuit, so that the fingerprint identification device can complete the collection of the electrical signals output by all the fingerprint identification circuits set by the fingerprint identification device in the case that the residence time of the user's finger is short, thereby supporting the design of fingerprint identification circuits with larger area and higher density in the optical fingerprint identification device.