Combined Inductive-Capacitive Sensing Circuit for Multi-Object Detection
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Solution Overview
Problem
Existing touch sensors require separate circuitry and sense elements to detect different types of objects, which is not feasible in terms of cost or space, especially in small form factor devices, as they respond differently to various touch types and objects.
Innovation Solution
A combined inductive and capacitive sensing circuitry that can switch between modes to detect objects using either capacitive or inductive sensing techniques, sharing the same sense unit and circuitry to measure both capacitance and inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate circuitry and sense elements are used to detect different types of objects, then detection capability for various objects is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent implements a single sense unit that can operate in multiple sensing modes (capacitive and inductive) by switching between different measurement techniques. The same physical sensor structure is used to detect both conductive objects (via capacitive coupling) and non-conductive objects (via inductive coupling), eliminating the need for separate sense elements for different object types.
Solution Approach 2:
The patent combines capacitive sensing circuitry and inductive sensing circuitry into a single integrated system. The sense unit incorporates both capacitive measurement capabilities (measuring change in capacitance) and inductive measurement capabilities (measuring change in inductance), allowing both sensing modalities to coexist in one unified circuit architecture.
2Adaptability or versatility
If separate circuitry and sense elements are used to detect different types of objects, then detection capability for various objects is improved, but space requirements increase
Solution Approach 1:
The patent implements a single sense unit that can operate in multiple sensing modes (capacitive and inductive) by switching between different measurement techniques. The same physical sensor structure is used to detect both conductive objects (via capacitive coupling) and non-conductive objects (via inductive coupling), eliminating the need for separate sense elements for different object types.
Solution Approach 2:
The patent combines capacitive sensing circuitry and inductive sensing circuitry into a single integrated system. The sense unit incorporates both capacitive measurement capabilities (measuring change in capacitance) and inductive measurement capabilities (measuring change in inductance), allowing both sensing modalities to coexist in one unified circuit architecture.
3Adaptability or versatility
If multiple sense units are used to detect different object types, then detection versatility is improved, but manufacturing cost increases
Solution Approach 1:
The patent implements a single sense unit that can operate in multiple sensing modes (capacitive and inductive) by switching between different measurement techniques. The same physical sensor structure is used to detect both conductive objects (via capacitive coupling) and non-conductive objects (via inductive coupling), eliminating the need for separate sense elements for different object types.
Solution Approach 2:
The patent combines capacitive sensing circuitry and inductive sensing circuitry into a single integrated system. The sense unit incorporates both capacitive measurement capabilities (measuring change in capacitance) and inductive measurement capabilities (measuring change in inductance), allowing both sensing modalities to coexist in one unified circuit architecture.
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 detection of various objects using a single sense unit and circuitry, reducing the need for multiple components and improving sensitivity to different touch types and objects, suitable for small form factor devices.
Implementation Method 1
measuring a capacitance of the sense unit... the measured capacitance indicates a presence of a conductive object
Implementation Method 2
measuring an inductance of the sense unit... the measured inductance indicates a presence of a non-conductive object
Data Source
AI summary
A sense unit for inductive sensing or capacitive sensing is described. The sense unit may include a first terminal coupled to a first node, a first electrode coupled to the first node, and a second terminal. The sense unit may include a second electrode coupled to the second terminal. In a first mode, a first signal is received at the first terminal and a second signal is output on the second terminal, where the second signal may be representative of a capacitance of the sense unit. The sense unit may include an inductive coil. The sense unit may include a first capacitor. The inductive coil and the first capacitor are coupled in parallel between the first node and ground. In a second mode, a third signal is received at the first terminal and a fourth signal is output on the second terminal.