Edge Proximity and Force Sensor Using Capacitance Shielding
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Solution Overview
Problem
Existing electronic devices lack effective methods for simultaneously detecting touch and proximity on their edges, which limits their ability to provide nuanced user interactions and adapt user interfaces accordingly.
Innovation Solution
A combined proximity and force sensor system utilizing first and second electrodes separated by a compressible material, with a third electrode functioning as a ground shield, allows for both force sensing and proximity sensing by measuring changes in capacitance, enabling detection of touch and proximity on edges through different operational modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate proximity sensors and force sensors are used, then sensing functionality is comprehensive, but device complexity increases
Solution Approach 1:
The patent combines proximity sensing and force sensing capabilities into a single sensor assembly. The sensor includes first and second electrodes for force sensing separated by a compressible material, and a third electrode for proximity sensing, all integrated within the same structural unit. This merging allows the device to achieve comprehensive sensing functionality while reducing overall device complexity by eliminating the need for separate sensor components.
Solution Approach 2:
The sensor assembly is designed to perform multiple functions: it can operate in force sensing mode by measuring capacitance changes between the first and second electrodes, and in proximity sensing mode by measuring capacitance changes of the third electrode. The same physical structure serves dual purposes, allowing the device to detect both applied force and proximity of objects without requiring separate specialized sensors for each function.
2Measurement precision
If multiple electrodes are used for simultaneous proximity and force sensing, then sensing precision is improved, but manufacturing complexity increases
Solution Approach 1:
The sensor is divided into distinct functional components: first and second electrodes for force sensing, and a third electrode for proximity sensing. Each electrode is positioned and configured to perform its specific function, allowing for precise measurement capabilities. The segmentation of sensing functions into separate electrode pairs enables high measurement precision while maintaining a relatively simple overall structure that can be manufactured using standard techniques.
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 advanced user interaction capabilities by accurately detecting force and proximity on edges, allowing for adaptive user interface changes and enhanced input mechanisms, such as altering displayed elements based on edge interactions.
Implementation Method 1
determining an applied force based on a first change in capacitance between the first and second electrodes related to compression of the compressible material
Implementation Method 2
sensing proximity of an object based on a second change in capacitance of the third electrode
Data Source
AI summary
In various implementations, a sensor operates in a force sensing mode by determining an applied force based on a first change in capacitance between first and second electrodes related to compression of a compressible material positioned between while the third electrode functions as a shield and in a proximity sensing mode by sensing proximity of an object based on a second change in capacitance of the third electrode while the first and/or second electrodes function as a shield. In some implementations, a device has a cover glass including a surface having a display area, an edge surface, and a cavity; a touch sensing electrode oriented toward the surface; an electrode positioned in the cavity oriented toward the edge surface; and a processing unit operable to detect touch or proximity of an object to the edge surface based on a change in capacitance between the electrode and the object.