Capacitive Housing Sensor Layout for Reliable Proximity Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electronic devices face challenges in accurately detecting when they are in use or activated, leading to inefficient power management and potential battery life reduction due to the lack of reliable methods to differentiate between active and inactive states.
Innovation Solution
The implementation of a capacitive sensor system within a housing with a partially conductive or electrically conductive element, which determines contact or proximity to an object by analyzing the rate of capacitance charge, allowing for effective power management transitions between low-power and high-power modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a capacitive sensor is enclosed by a housing with insulating material, then the sensor is protected from environmental damage, but the sensing sensitivity and range are reduced due to increased separation distance
Solution Approach 1:
A conductive element is introduced as an intermediary between the capacitive sensor electrode and the external environment. This conductive element extends the sensing field beyond the insulating housing while maintaining sensor protection, effectively mediating between the need for protection and the need for sensitivity.
Solution Approach 2:
The sensing capability is extended from the immediate vicinity of the sensor electrode to a broader spatial region through the conductive element. This creates an extended sensing dimension that penetrates through the insulating housing barrier, allowing detection at greater distances without compromising sensor protection.
2Reliability
If the separation distance between the sensor electrode and external environment is increased for protection, then the sensor is shielded from damage, but the capacitance change signal becomes weaker
Solution Approach 1:
The conductive element is electrically connected to the sensor electrode, merging their electrical functions. This combination allows the sensor electrode's sensing capability to extend through the conductive element, maintaining strong capacitance change signals even when the physical separation distance is increased for protection.
3Ease of operation
If conventional on/off switches are used to determine device activation, then the device can be turned on and off, but the switches may be inadvertently operated resulting in battery life consumption
Solution Approach 1:
The mechanical on/off switch system is replaced with a capacitive sensing system that detects device activation through capacitance changes. This substitution eliminates the need for physical switch operations, preventing inadvertent activation and the associated battery life consumption while maintaining ease of intentional activation.
Solution Approach 2:
The capacitive sensor automatically detects when the device is picked up or activated by the user through changes in capacitance, enabling the device to self-determine its active state without requiring manual switch operations. This self-service mechanism prevents inadvertent battery consumption.
4Measurement precision
If the processor clock rate is increased to improve sensing resolution, then the detection accuracy improves, but the power consumption increases
Solution Approach 1:
Instead of increasing the processor clock rate to improve sensing resolution, the patent changes the physical parameters of the sensing system by introducing a conductive element. This parameter change extends the sensing range and improves detection capability without requiring higher processing speeds, thereby avoiding increased power consumption.
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 solution enhances the sensitivity and range of capacitive sensing without increasing device size or processor speed, effectively managing power consumption and extending battery life by accurately detecting device activation and usage.
Implementation Method 1
The controller is configured to determine whether the electronic device is in contact or in close proximity to an object based at least in part on a rate of capacitance charge of the capacitor when the capacitive sensor is energized
Implementation Method 2
At least a first portion of the housing includes an electrically insulating material and at least a second portion of the housing includes a partially conductive material, where the at least one sensor electrode is in conductive contact with the second portion of the housing and separated from the outer surface by the housing
Data Source
AI summary
Disclosed are electronic devices for detecting contact or close proximity to an object to be detected. An electronic device includes a capacitive sensor enclosed by a housing and a controller coupled to the capacitive sensor, where the controller is configured to detect contact or close proximity to an object to be detected, and where the capacitive sensor includes a capacitor with a sensor electrode. The sensor electrode is separated from an outer surface of the housing by the housing. At least a portion of the housing includes a partially conductive material and the sensor electrode is in conductive contact with the partially conductive material, or the sensor electrode is in conductive contact with an electrically conductive element on an inner surface of the housing or at least partially embedded in the housing.