Capacitive Sensor Ring for Multi-Axis Input Detection
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Solution Overview
Problem
Existing input devices struggle to accurately detect multiple types of motion, such as rotation, translation, and tilt, with existing technologies often requiring complex configurations and excessive components, while also maintaining a watertight seal.
Innovation Solution
A capacitive sensor system with multiple planes of capacitive elements, where a moveable member alters the positions of capacitive elements relative to each other, using a dielectric to facilitate movement and return to default positions, allowing for the detection of various motions based on capacitance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing sensor configurations are used to detect multiple types of motion, then measurement capability is improved, but device complexity increases
Solution Approach 1:
The capacitive sensor system uses a single sensor structure with multiple capacitive elements that can detect multiple types of motion (rotation, translation, tilt) simultaneously. The sensor ring includes first, second, and third capacitive elements arranged to detect different motion components, allowing one device to perform multiple measurement functions without requiring separate sensors for each motion type.
Solution Approach 2:
The capacitive sensor is divided into multiple discrete capacitive elements (first, second, and third capacitive elements) with different orientations and positions. Each element is segmented to detect specific motion components, with the first element detecting rotation about the longitudinal axis, the second element detecting translation along the longitudinal axis, and the third element detecting tilt. This segmentation allows complex multi-axis motion detection through coordinated readings from individual simple elements.
2Reliability
If a watertight seal is maintained while allowing sensor movement, then sealing reliability is improved, but measurement precision deteriorates
Solution Approach 1:
A dielectric member is introduced as an intermediary component between the capacitive elements and the moveable member. This dielectric member allows the moveable member to move relative to the capacitive elements while maintaining a watertight seal. The dielectric enables capacitive coupling without direct mechanical contact, preserving both the seal integrity and the ability to detect motion through capacitance changes.
Solution Approach 2:
The patent replaces traditional mechanical contact-based motion detection with a capacitive sensing system. Instead of using mechanical switches or contact sensors that would compromise the watertight seal, the system uses changes in capacitance between the capacitive elements and the moveable member to detect motion. This electrical field-based approach allows motion detection while maintaining the seal, as no mechanical openings or contacts are required.
3Device complexity
If minimal components are used, then device complexity is reduced, but reliability deteriorates
Solution Approach 1:
Each capacitive element is positioned and oriented with specific local qualities to detect particular motion components. The first capacitive element is positioned to detect rotation about the longitudinal axis, the second element is positioned to detect translation along the longitudinal axis, and the third element is positioned to detect tilt. This localized optimization of each element's position and orientation ensures that the minimal component configuration still provides reliable detection of all required motion types.
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
The system effectively determines multiple types of motion with a minimal component configuration, providing accurate input signals and maintaining a watertight seal, enabling efficient and precise user input detection.
Implementation Method 1
The capacitive sensors have first capacitive elements coupled to the manipulation mechanism, second capacitive elements, and a dielectric positioned between. Movement of the manipulation mechanism alters the positions of the first and second capacitive elements with respect to each other. The movement is determinable based on capacitance changes that result therefrom.
Implementation Method 2
A capacitive sensor system with multiple planes of capacitive elements, where a moveable member alters the positions of capacitive elements relative to each other, using a dielectric to facilitate movement and return to default positions
Data Source
AI summary
An input mechanism for a portable electronic device includes a rotational manipulation mechanism, such as a cap or shaft. The input mechanism also includes a sensor having first capacitive elements coupled to the manipulation mechanism, second capacitive elements, and a dielectric positioned between the first and second capacitive elements. Movement of the manipulation mechanism alters the positions of the first and second capacitive elements with respect to each other and is determinable based on capacitance changes resulting therefrom. In some implementations, the second capacitive elements may be part of an inner ring or partial ring nested at least partially within an outer ring or partial ring.