Capacitive Input Sensing Regimes for Glove and Hover Detection
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Solution Overview
Problem
Proximity sensor devices struggle to accurately detect user input, especially when objects are farther away from the surface or when users wear gloves, due to limitations in capacitive sensing technology.
Innovation Solution
Implementing a processing system that operates in multiple sensing regimes with different duty cycles of absolute capacitive sensing and transcapacitive sensing, allowing for accurate detection of objects both at and away from the surface, including gloved fingers, by selectively switching between regimes based on contact information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If proximity sensor devices use standard capacitive sensing, then they can detect objects at the surface, but they cannot reliably detect objects farther away from the surface
Solution Approach 1:
The system dynamically switches between absolute capacitive sensing and transcapacitive sensing modes based on detected input conditions. When a hovering input is detected, the system transitions to transcapacitive sensing mode to maintain accurate position determination for objects farther from the surface, whereas conventional systems use a fixed sensing mode that cannot adapt to varying input distances.
Solution Approach 2:
The system changes sensing parameters by switching between different capacitive sensing modes (absolute vs. transcapacitive) with different duty cycles. This parameter change allows the system to extend its effective sensing range while maintaining measurement precision, as transcapacitive sensing is more sensitive to objects at greater distances from the surface.
2Ease of operation
If gloves are worn, then user comfort is improved, but the proximity sensor device cannot reliably detect the position of the gloved finger
Solution Approach 1:
The system adapts its sensing mode dynamically in response to the dielectric properties introduced by gloves. When input is detected through a glove medium, the system switches to transcapacitive sensing mode which maintains sensitivity and position detection accuracy despite the additional dielectric layer, allowing users to wear gloves for comfort without sacrificing input accuracy.
3Device complexity
If a single capacitive sensing mode is used, then device complexity is reduced, but the system cannot accurately determine position for both touching and hovering inputs
Solution Approach 1:
The system achieves multi-functionality by implementing both absolute capacitive sensing and transcapacitive sensing modes within a single device. This allows the same device to accurately detect both touching inputs (using absolute capacitive sensing) and hovering inputs (using transcapacitive sensing), as well as inputs through gloves, without requiring separate specialized devices for each input type.
4Measurement precision
If transcapacitive sensing duty cycle is increased, then hovering input detection is improved, but power consumption increases
Solution Approach 1:
The system uses periodic switching between sensing modes with different duty cycles. Transcapacitive sensing, which is more power-consuming but better for hovering detection, is activated periodically when hovering input is detected rather than continuously. This periodic action maintains detection accuracy while reducing overall power consumption compared to continuous transcapacitive sensing.
Solution Approach 2:
The system dynamically adjusts the duty cycle of transcapacitive sensing based on the detected input state. When hovering input is detected, the duty cycle is increased to improve detection accuracy. When no hovering input is present, the duty cycle is reduced to minimize power consumption. This dynamic adjustment optimizes the trade-off between detection performance and energy usage.
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
Enhances the flexibility and usability of input devices by reliably detecting user input regardless of object proximity to the surface, improving accuracy for both touching and hovering inputs.
Implementation Method 1
a sensor module configured to operate a plurality of capacitive sensor electrodes to selectively perform transcapacitive sensing and absolute capacitive sensing to detect input objects
Implementation Method 2
a determination module configured to determine positional information for input objects in the sensing region by selectively operating the processing system in a first sensing regime and a second sensing regime
Data Source
AI summary
The embodiments described herein thus provide devices and methods that facilitate improved input devices. Specifically, the devices, systems and methods provide the ability to accurately determine user input using multiple different sensing regimes. The different sensing regimes can be used to facilitate accurate position determination of objects both at the surface and away from the surface. For example, the different sensing regimes can be used to determine position information for both ungloved and gloved fingers. In one embodiment the first sensing regime uses a first duty cycle of absolute capacitive sensing and a first duty cycle of transcapacitive sensing. The second sensing regime uses a second duty cycle of absolute capacitive sensing and a second duty cycle of transcapacitive sensing, where the second duty cycle of absolute capacitive sensing is greater than the first duty cycle of absolute capacitive sensing.