Fingerprint Sensor Electrode Segmentation for Sensitivity
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Solution Overview
Problem
The capacitance type fingerprint detection technology faces challenges with high material and manufacturing costs, low product lifetime, and tolerance due to weak sensing signals and strong noise signals, necessitating improvements in sensing sensitivity and signal-to-noise ratio, as well as the integration of sensing electrodes into a protection glass or display panel.
Innovation Solution
A fingerprint identification device utilizing multiple selecting switch components to dynamically divide electrode areas into sensing and deflection electrode blocks, enhancing sensitivity and accuracy by manipulating electric flux lines and increasing the sensing distance, while reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the sensing electrodes are integrated into a protection glass or display panel, then the cost is reduced and product lifetime is increased, but the sensing sensitivity and signal-to-noise ratio deteriorate due to weak sensing signals and strong noise signals
Solution Approach 1:
The patent divides the electrode array into multiple electrode areas with dedicated sensing signal lines, allowing selective activation of sensing regions. This segmentation enables the system to maintain high sensing sensitivity in specific areas while reducing overall system complexity and cost.
Solution Approach 2:
The patent implements dynamic electrode configuration where electrode areas can be sequentially or dynamically divided into sensing electrode blocks and deflection electrode blocks. This dynamic switching allows the system to adapt sensing sensitivity to different operational requirements, maintaining high precision when needed while reducing power consumption and cost during normal operation.
2Duration of action of stationary object
If the sensing electrodes are integrated into a protection glass or display panel, then the product lifetime and tolerance are increased, but the sensing distance and accuracy deteriorate
Solution Approach 1:
The patent introduces deflection electrodes as intermediary elements between the sensing electrodes and the fingerprint. These deflection electrodes manipulate electric flux lines to enhance the sensing signal strength, thereby maintaining accurate fingerprint detection even when sensing electrodes are integrated into the protection glass at a greater distance from the fingerprint.
3Measurement precision
If multiple electrode areas are used to improve sensing sensitivity, then the sensing accuracy is enhanced, but the device complexity increases
Solution Approach 1:
The patent designs electrode areas that can serve multiple functions: they can be configured as sensing electrode blocks for fingerprint detection, deflection electrode blocks for signal enhancement, or reference electrode blocks for noise cancellation. This multi-functionality allows the system to maintain high sensing accuracy while reducing the number of dedicated components, thereby simplifying the overall device structure.
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 solution enhances sensing sensitivity, stability, and accuracy, improves the signal-to-noise ratio, and reduces costs by allowing the sensing electrodes to be integrated into a protection glass or display panel, thereby extending the product's lifetime and tolerance.
Implementation Method 1
the capacitance type stands out in this field by its size, cost, power saving, stability and anti-fake function
Implementation Method 2
gathering and pulling up the electric flux lines from the electrodes in the sensing area
Data Source
AI summary
A fingerprint identification device includes a substrate, at least two electrode areas, at least one dedicated sensing signal line, plural electrode selection switch groups, and plural signal lines. Each electrode area has plural electrodes. The signal lines are divided into plural first directional signal lines and plural second directional signal lines. The first directional signal lines are perpendicular to the second directional signal lines. The plural electrode selection switch groups sequentially or dynamically select at least one electrode as a sensing electrode block in each electrode area. The plural electrode selection switch groups configure the electrodes surrounding the sensing electrode block as at least two corresponding deflection electrode blocks. Each sensing electrode block is corresponding to at least two deflection electrode blocks. Each deflection electrode block has plural electrodes.