Fingerprint Sensing Control Method for In-Cell Touch Panels
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Solution Overview
Problem
Touch panels with in-cell structures face challenges in determining hover operations due to small capacitance variances generated by reduced touch pad areas, leading to decreased sensitivity and increased power consumption.
Innovation Solution
A touch control method that groups multiple sensing units to enhance sensitivity by adjusting the number of connected touch units and sensing areas, allowing for increased capacitance variances detection and reduced power consumption through switching between normal and grouping modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the area of each touch pad is reduced to achieve greater touch resolution, then the touch resolution is improved, but the capacitance variance becomes too small to reliably determine hover operations
Solution Approach 1:
The patent combines multiple sensing units into groups to form virtual sensing areas. By merging the capacitance signals from multiple individual sensing units, the system generates larger capacitance variances that can be reliably detected for hover operations, while still maintaining the fine touch resolution enabled by the small physical sensing unit areas.
2Reliability
If multiple sensing units are grouped together to increase sensitivity and capacitance variance detection, then hover operation determination is improved, but the touch resolution may be degraded
Solution Approach 1:
The patent implements dynamic switching between different sensing modes. The system can switch between individual sensing unit mode (for high resolution touch detection) and grouped sensing unit mode (for high sensitivity hover detection). This dynamic adaptation allows the system to optimize for the current operational need without permanently sacrificing either resolution or sensitivity.
Solution Approach 2:
The patent segments the sensing system into multiple operational modes with different grouping configurations. By dividing the sensing units into different groups or combining them in various ways, the system can selectively activate the appropriate sensing configuration based on whether touch resolution or hover sensitivity is the primary requirement.
3Measurement precision
If the scanning frequency is increased to improve detection accuracy, then the sensitivity is improved, but the power consumption increases
Solution Approach 1:
The patent implements periodic scanning with variable frequencies. Instead of continuous high-frequency scanning, the system performs scanning at different frequencies based on operational context. During hover detection, scanning can be performed at higher frequencies to capture capacitance changes, while during stable touch states, scanning frequency is reduced to minimize power consumption.
Solution Approach 2:
The patent dynamically changes scanning parameters including frequency and duration based on detected conditions. When hover operations are detected or suspected, the system increases scanning frequency to improve detection accuracy. When no hover activity is detected, the system reduces scanning frequency to conserve power, thus adapting the energy consumption to the actual operational requirements.
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 method increases the sensitivity of touch devices while reducing power consumption by enlarging capacitance variances detectable during hover operations and optimizing scanning frequencies.
Implementation Method 1
The touch panel of the in-cell structure senses the touches according to capacitance variances of a plurality of touch pads in response to the touches
Data Source
AI summary
A fingerprint sensing control method for sensing one or more sensing signals from a fingerprint sensing device having a plurality of sensing areas, each of the sensing areas having a plurality of sensing units, the sensing control method includes determining a sensitivity of the fingerprint sensing device; and obtaining the one or more the fingerprint sensing signals from the fingerprint sensing device, wherein one or more of the plurality of sensing units are grouped so as to achieve the sensitivity, and for a first sensitivity of the sensing device, a first number of one or more sensing units are grouped, and for a second sensitivity of the fingerprint sensing device, a second number of one or more sensing units are grouped, and the second sensitivity is greater than the first sensitivity and the second number is greater than the first number.