Dual-Mode Sense Unit for Combined Capacitive and Inductive Detection
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Solution Overview
Problem
Conventional touch sensors require separate sense elements and circuits for capacitive and inductive sensing, making it costly and space-intensive to detect different types of objects, especially in small form factor devices.
Innovation Solution
A hybrid sensing circuit that can operate in both capacitive and inductive modes using a single sense unit, employing a signal generator and charge measurement circuit to measure capacitance and inductance, respectively, allowing detection of various objects using combined capacitive and inductive sensing techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate sense elements and circuits are used for capacitive and inductive sensing, then detection capability for different object types is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent implements a single sense unit that can operate in both capacitive and inductive sensing modes by dynamically reconfiguring the sensing circuitry. The sense unit includes a sensing electrode and associated circuitry that can be switched between capacitive coupling configuration and inductive coupling configuration, allowing one component to perform multiple detection functions for different object types (conductive vs. ferrous objects).
Solution Approach 2:
The patent combines capacitive and inductive sensing circuits into a single integrated sense unit. The sensing electrode serves dual purposes: it forms a capacitive sensor when coupled with a first sensing circuit and an inductive sensor when coupled with a second sensing circuit. This merging eliminates the need for separate sense elements and reduces overall device complexity.
2Adaptability or versatility
If separate sense elements and circuits are used for capacitive and inductive sensing, then detection capability for different object types is improved, but space requirements increase
Solution Approach 1:
The single sense unit with reconfigurable circuitry allows one physical component to provide both capacitive and inductive sensing capabilities, significantly reducing the area required compared to having separate sense elements for each sensing type.
Solution Approach 2:
By merging the capacitive and inductive sensing functions into a single sense unit with shared sensing electrode and reconfigurable circuitry, the patent reduces the total space required in the display assembly while maintaining full detection capability for both conductive and ferrous objects.
3Measurement precision
If separate sensing circuits are used for capacitive and inductive modes, then sensing accuracy for specific object types is improved, but manufacturing cost increases
Solution Approach 1:
The reconfigurable sense unit provides both capacitive and inductive sensing capabilities through a single component, reducing the total number of parts that need to be manufactured and assembled, thereby lowering manufacturing costs while maintaining sensing accuracy for both object types.
Solution Approach 2:
The integration of dual-mode sensing circuitry into a single sense unit simplifies the manufacturing process by reducing component count and assembly steps, while the specialized circuit paths for each sensing mode ensure that measurement precision is maintained for both capacitive and inductive detection.
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 efficient detection of different types of objects, including ferrous and non-ferrous metals, within a single device form factor by sharing sensing components, reducing cost and space requirements.
Implementation Method 1
a first sensing circuit to measure a capacitance of the sense unit when the first signal is applied to the sense unit
Implementation Method 2
a second sensing circuit to measure an inductance of the sense unit when the third signal is applied to the sense unit
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.