Shield Electrode Voltage Transition for Ion-Migration Reduction
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Solution Overview
Problem
Proximity sensor devices with transparent electrodes face issues of ion-migration due to strong electromagnetic fields, leading to corrosion and reduced longevity, especially when combined with moisture, humidity, and impurities.
Innovation Solution
The implementation of a processing system with a sensor module and a determination module, which includes transmitter electrodes, receiver electrodes, and a shield electrode, where the shield electrode's voltage is transitioned during non-sensing periods to mitigate the electromagnetic field and reduce ion-migration between electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the space between adjacent electrodes is reduced to increase the number of electrodes, then the electromagnetic field strength increases, but ion-migration rate increases leading to corrosion and reduced longevity
Solution Approach 1:
A shield electrode is introduced as an intermediary element positioned between the transmitter and receiver electrodes. This shield electrode creates a counteracting electromagnetic field that reduces the net field strength between adjacent electrodes, thereby decreasing ion-migration rates and preventing corrosion while allowing electrodes to be placed closer together
Solution Approach 2:
The voltage of the shield electrode is dynamically adjusted between a first voltage during sensing time periods and a second voltage during non-sensing time periods. This parameter change optimizes the electromagnetic field control to minimize ion-migration while maintaining sensing functionality
2Illumination intensity
If transparent electrodes are used to prevent obscuring the display region, then optical clarity is improved, but the strong electromagnetic field increases ion-migration rate causing corrosion
Solution Approach 1:
The shield electrode acts as a mediator that reduces the electromagnetic field strength between transparent electrodes, thereby protecting them from ion-migration and corrosion while maintaining their optical clarity properties
Solution Approach 2:
The shield electrode voltage is periodically changed between sensing and non-sensing time periods, creating a dynamic protection mechanism that reduces ion-migration during non-sensing periods while maintaining sensing capability during sensing periods
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 effectively reduces ion-migration, thereby increasing the longevity and performance of the electrodes by minimizing corrosion and improving conductivity and optical clarity.
Implementation Method 1
The strength of the electromagnetic field between electrodes is inversely proportional to the square of the distance between the electrodes
Implementation Method 2
a strong electromagnetic field will increase the rate at which ions migrate between the electrodes, resulting in corrosion
Data Source
AI summary
Embodiments of the present invention generally provide a processing system for an input device including a sensor module having sensor circuitry. The sensor module may be coupled to transmitter electrodes, receiver electrodes, and a shield electrode. The sensor module may be configured for transmitting transmitter signals with the transmitter electrodes, receiving resulting signals with the receiver electrodes, and transitioning the shield electrode from a first voltage to a second voltage during a non-sensing time period. The resulting signals may include effects which correspond to the transmitter signals. The input device may further include a determination module configured for determining positional information for an input object based at least in part on the resulting signals.