Capacitive Input Sensing with Polarity Matrices for Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing input devices face challenges in selecting a drive matrix that simplifies calculations while balancing the number of positive and negative drive signals, which affects detection sensitivity and noise reduction, limiting the flexibility in selecting appropriate matrices for various detection positions.
Innovation Solution
The input device employs a sensor unit that generates composite detection signals by controlling the polarity of detection signals at multiple detection positions, using a processor to regenerate signal levels based on inverse matrix calculations, allowing for independent polarity pattern matrices for each detection position group and reducing noise by dispersing it across multiple groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a drive matrix is selected to simplify inverse matrix calculations, then calculation complexity is reduced, but the ability to balance positive and negative drive signals is limited
Solution Approach 1:
The patent divides the detection positions into multiple groups and assigns different polarity patterns to each group. This segmentation allows the system to use simplified matrices for calculation while maintaining the ability to balance drive signals across different groups, thus resolving the contradiction between calculation simplicity and signal balancing capability.
Solution Approach 2:
The patent dynamically selects polarity patterns based on the detection position group, allowing the system to adapt the drive matrix selection to specific operational requirements. This dynamic approach enables the use of simplified matrices in certain contexts while maintaining signal balancing capability in others.
2Measurement precision
If the number of positive and negative drive signals is balanced, then detection sensitivity increases and noise is reduced, but the selection of suitable drive matrices becomes more difficult
Solution Approach 1:
By segmenting detection positions into groups and assigning specific polarity patterns to each group, the patent enables balanced drive signals across the entire detection area while using manageable matrix sizes for each segment, thus improving detection sensitivity without excessive complexity.
Solution Approach 2:
The patent changes the polarity parameters of drive signals in a systematic manner across different detection position groups. This parameter variation allows the system to achieve balanced positive and negative signals for improved sensitivity while maintaining controlled matrix complexity through structured parameter management.
3Measurement precision
If multiple polarity patterns are used for different detection position groups, then noise is dispersed and detection sensitivity is enhanced, but the overall system complexity increases
Solution Approach 1:
The patent segments the detection area into multiple position groups, each using different polarity patterns. This segmentation disperses noise across different groups while maintaining manageable complexity within each segment, achieving noise reduction without proportionally increasing overall system complexity.
Solution Approach 2:
The patent applies polarity patterns selectively to different detection position groups rather than uniformly across all positions. This partial application approach achieves noise dispersion and sensitivity enhancement in critical areas while avoiding the complexity increase that would result from applying complex patterns everywhere.
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 increases the degree of freedom in selecting polarity patterns, enhances detection sensitivity, and reduces noise by allowing independent matrix selection for each detection position group, improving signal regeneration and noise management.
Implementation Method 1
an input device that detects proximity of an operation object, such as a finger, by measuring a physical quantity, such as an electric capacitance, at a plurality of detection positions in a detection area
Implementation Method 2
a plurality of parallel drive electrodes disposed on one layer and a plurality of parallel detection electrodes disposed on another layer, where the drive electrodes and the detection electrodes intersect at the electrode unit
Implementation Method 3
a drive signal of either positive or negative polarity is applied simultaneously to a plurality of drive electrodes
Data Source
AI summary
There is provided a sensor unit for detecting a proximity state of an object at N detection positions, generating a composite detection signal in conformity with the sum of N detection signals obtained as a result of detection for N detection positions, and controlling a positive or negative polarity of the detection signal having a signal level in conformity with the proximity state at each of N detection positions, a sensor control unit for controlling the sensor unit for generating M composite detection signals having N polarity patterns set at N detection signals different from each other, and a signal regeneration unit for regenerating the signal level of the N detection signal based on the M composite detection signals generated by the sensor unit.