Multiline Proximity Detection Using Hadamard Matrix Computation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional proximity detection devices face inefficiencies due to line-sequential driving, requiring high-speed computers and experiencing crosstalk issues when patterns applied to transmitting electrodes are not completely orthogonal.
Innovation Solution
A proximity detection device and method that applies periodic alternating voltages to multiple transmitting electrodes using a multiline driving unit, employing a computing unit with a linear computing unit that converts current values into electrostatic capacitance values by treating patterns as matrices and using an inverse matrix, and storing interim results in a memory unit for faster computation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If line-sequential driving is used to apply voltages to transmitting electrodes, then the detection process is simpler to implement, but the detection efficiency and speed are reduced
Solution Approach 1:
The patent segments the driving process by dividing transmitting electrodes into multiple groups, where each group is driven simultaneously with distinct waveforms. This allows parallel processing of multiple electrode lines while maintaining manageable control complexity through structured grouping and waveform assignment.
Solution Approach 2:
The patent employs periodic alternating voltages with distinct waveforms applied to different transmitting electrode groups in a cyclic manner. This periodic action enables simultaneous driving of multiple electrodes while maintaining signal distinguishability through waveform timing and pattern differentiation.
2Productivity
If multiple transmitting electrodes are driven simultaneously with different patterns, then the detection speed increases, but the computation amount increases and high-speed computers are required
Solution Approach 1:
The patent changes the waveform parameters (frequency, phase, amplitude patterns) of voltages applied to different transmitting electrode groups. By encoding spatial information into distinct waveform parameters, the system enables parallel electrode driving while reducing computation complexity through waveform-based signal differentiation rather than complex matrix operations.
Solution Approach 2:
The patent performs preliminary waveform assignment and pattern differentiation before the actual detection process. By pre-defining distinct waveforms for each transmitting electrode group and establishing their temporal and spectral relationships in advance, the system reduces real-time computation requirements during detection.
3Device complexity
If patterns applied to transmitting electrodes are not completely orthogonal, then the device complexity is reduced, but crosstalk occurs in the correlation computation result
Solution Approach 1:
The patent incorporates feedback mechanisms where correlation computation results are used to adjust and optimize waveform patterns. By continuously monitoring detection accuracy and adjusting waveform orthogonality parameters based on measured crosstalk levels, the system maintains detection precision while allowing for practical, non-ideal pattern implementations.
Solution Approach 2:
The patent applies preliminary anti-action by designing waveforms with pre-compensated orthogonality characteristics. Before actual detection, the system pre-adjusts waveform parameters to counteract expected crosstalk effects, ensuring that even with non-completely orthogonal patterns, the final measurement accuracy is maintained through anticipatory correction.
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
Enables high-speed detection without crosstalk and reduced power consumption, even at lower voltages, by utilizing Hadamard matrices for efficient computation and noise reduction.
Implementation Method 1
The alternating voltage is transmitted to the receiving electrode 4 by the electrostatic coupling of the intersection between the transmitting electrode 3 and the receiving electrode 4
Implementation Method 2
when an object of a human finger or the like approaches between two closely located electrodes, the electrostatic capacitance between the electrodes changes
Data Source
AI summary
A proximity detection device has transmitting and receiving electrodes and a multiline driving unit that simultaneously applies periodic alternating voltages to at least two of the transmitting electrodes. A measurement unit measures currents or amounts of accumulated charge from the receiving electrodes in synchronization with the simultaneous application of periodic alternating voltages to the at least two transmitting electrodes by the multiline driving unit. A linear computing unit performs linear computation of measurement results from a measurement unit in response to electrostatic capacitances of respective intersections between the transmitting and receiving electrodes. The linear computing unit has a memory unit that stores an output of the linear computation for readout at plural times. A proximity computing unit performs a computation to determine an approach and/or a position of an object relative to a detection area based on the output from the linear computing unit stored in the memory unit.