Capacitive On-Head Detection Using Conductive BCT Frame
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wearable computing devices face challenges in extending battery life without requiring additional sensors to detect when the device is being worn, as existing sensing mechanisms can be cumbersome and power-intensive.
Innovation Solution
A bone conduction transducer (BCT) is used as a capacitive sensor to detect capacitance between the device and the wearer's body, allowing the device to switch between power states based on whether it is being worn, thereby conserving power without additional hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional sensors are added to detect when the device is being worn, then detection accuracy is improved, but device complexity and power consumption increase
Solution Approach 1:
The BCT frame is designed to serve dual purposes: as a structural support component and as a capacitive sensor. By making the frame conductive and utilizing its inherent capacitance with the wearer's body, the patent eliminates the need for separate sensing mechanisms, thereby reducing device complexity while maintaining detection capability
Solution Approach 2:
The BCT frame utilizes its own electrical properties (capacitance) to perform the sensing function. The frame's capacitance with the wearer's body provides the detection signal, allowing the structure itself to serve as the sensor rather than requiring an external sensing component
2Measurement precision
If additional sensors are added to detect when the device is being worn, then detection accuracy is improved, but power consumption increases
Solution Approach 1:
The BCT frame serves as both structural support and sensing element, eliminating the need for separate power-intensive sensors. The capacitive sensing using the frame's inherent properties consumes minimal power compared to dedicated sensors
Solution Approach 2:
The frame uses its own electrical capacitance properties to generate the detection signal, avoiding the need for active sensing components that require continuous power supply. The sensing mechanism leverages passive electrical properties already present in the structural component
3Duration of action of moving object
If the device operates in a lower power state when not in use, then battery life is extended, but detection capability may be reduced
Solution Approach 1:
The system periodically checks capacitance levels to detect wear status, allowing the device to remain in low-power state while maintaining intermittent detection capability. The periodic sensing enables the device to wake from power-saving mode only when necessary, balancing battery life and detection reliability
Solution Approach 2:
The BCT frame provides continuous passive capacitive sensing that can trigger wake events from power-saving mode. Since the frame's capacitance with the wearer's body is always present when worn, the detection system can reliably wake the device without requiring high-power continuous monitoring
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 method effectively extends battery life by allowing the device to operate in a lower power state when not in use, enhancing the device's power efficiency without the need for additional sensors.
Implementation Method 1
at least a portion of the BCT frame is conductive, wherein the conductive portion of the BCT frame is arranged to capacitively couple the BCT to a wearer when the wearable computing device is worn
Data Source
AI summary
The present application describes on-head detection by a capacitive sensing bone conduction transducer (BCT) system and applications thereof. An example apparatus includes a wearable computing device comprising: (1) the BCT comprising a transducer coupled to a BCT frame, wherein (a) the BCT frame couples the BCT to a component of the wearable computing device, (b) at least a portion of the BCT frame is conductive, wherein the conductive portion of the BCT frame is arranged to capacitively couple the BCT to a wearer when the wearable computing device is worn, and (c) the BCT is configured to receive and be driven by an audio signal; (2) a capacitive sensor controller; and (3) at least one connective component that further couples the conductive portion of the BCT frame to the capacitive sensor controller.