Capacitive Fold Angle Detection Without Gyro or Hall Sensors
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Solution Overview
Problem
Conventional foldable devices rely on gyroscopic sensors, accelerometers, and IR or Hall sensors to detect fold angles, which are prone to temperature sensitivity and require heavy filtering, leading to inaccuracies and increased material and assembly costs.
Innovation Solution
Utilize a capacitive sensor system with electrodes on either side of the fold line to measure absolute and transcapacitance to determine the fold angle, canceling out interference effects and eliminating the need for additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If gyroscopic sensors and accelerometers are used to detect fold angle, then fold angle detection is achieved, but temperature sensitivity and measurement precision deteriorate
Solution Approach 1:
The patent replaces mechanical sensors (gyroscopic sensors and accelerometers) with a capacitive sensing system that uses electrodes to detect fold angle through capacitance changes. This substitution eliminates the temperature sensitivity issues associated with mechanical sensors while maintaining accurate fold angle detection capability.
Solution Approach 2:
The patent uses existing capacitive touch sensor electrodes to create a virtual copy of the sensing function needed for fold angle detection. By repurposing the capacitive sensor system originally designed for touch input, the invention achieves fold angle detection without requiring separate dedicated sensors, thereby avoiding the temperature sensitivity problems of mechanical sensors.
2Reliability
If dedicated IR sensor or Hall sensor is used to detect closure, then closure detection is achieved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent makes the capacitive sensor system universal by enabling it to perform multiple functions: both touch input detection and fold angle/closure detection. The same electrodes and processing system used for touch sensing are repurposed to detect device closure state, eliminating the need for dedicated IR sensors or Hall sensors and reducing overall device complexity.
Solution Approach 2:
The patent merges the closure detection function with the existing capacitive touch sensing system. By combining these functions into a single sensor system, the invention reduces the total number of components, simplifies the sensor system architecture, and lowers manufacturing costs while maintaining reliable closure detection.
3Measurement precision
If gyroscopic sensors and accelerometers are used for fold angle detection, then fold angle measurement is achieved, but material cost and assembly complexity increase
Solution Approach 1:
The patent enables the capacitive sensor system to serve itself by using its inherent capacitance measurement capabilities to detect fold angle. The existing electrodes and signal processing infrastructure are leveraged to perform the additional function of fold angle measurement, eliminating the need for separate dedicated sensors and reducing assembly complexity.
Solution Approach 2:
The patent creates a functional copy of the sensing capability using the capacitive sensor system. Instead of adding physical mechanical sensors, the invention uses the electrical properties of existing capacitive electrodes to replicate the fold angle detection function, thereby simplifying manufacturing and assembly processes.
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
Accurately detects fold angles without temperature-related errors, reducing material costs and simplifying design while improving reliability by eliminating the need for gyroscopic and IR/Hall sensors.
Implementation Method 1
obtain at least one first absolute capacitance measurement via the at least one first electrode and at least one second absolute capacitance measurement via the at least one second electrode
Data Source
AI summary
A system for determining a fold angle and an open or closed state of a foldable device includes: a plurality of electrodes, including a first set of electrodes for performing absolute capacitance sensing and a second set of electrodes for performing transcapacitance sensing, wherein each of the second set of electrodes is farther from a fold line of the foldable device than each of the first set of electrodes; and a processing system, configured to: obtain absolute capacitance measurements via the first set of electrodes; obtain at least one transcapacitance measurement via at least one receiver electrode of the second set of electrodes; determine the fold angle of the foldable device based on the absolute capacitance measurements; and determine whether the foldable device is in an open state or a closed state based on the at least one transcapacitance measurement.