Flexible PCB Impedance Sensing for Fold Angle Detection
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Solution Overview
Problem
Existing foldable electronic devices face challenges in accurately determining the folding angle between housings, which affects their operational modes and functionality.
Innovation Solution
A flexible printed circuit board (FPCB) with specific sensing patterns and impedance detection mechanisms is used to identify the folding angle between housings, enabling precise angle determination and adaptive operational modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a flexible printed circuit board is used to connect components in a foldable device, then the device can be transformed between various configurations, but the accuracy of folding angle detection deteriorates
Solution Approach 1:
The FPCB is divided into multiple bending portions (first bending portion, second bending portion) with distinct sensing pattern parts. Each bending portion contains conductive lines arranged in specific patterns that respond to bending in different directions, enabling independent measurement of folding angles in different configurations
Solution Approach 2:
The patent replaces traditional mechanical angle sensors with an electrical impedance-based sensing system. The sensing pattern parts consist of conductive lines whose impedance changes in response to bending, allowing folding angle detection through electrical measurements rather than mechanical sensing
2Measurement precision
If sensing patterns are added to the FPCB for angle detection, then folding angle can be identified, but the device complexity increases
Solution Approach 1:
The FPCB serves multiple functions: it provides electrical connections between components and simultaneously acts as a sensing element for folding angle detection. The same conductive lines used for signal transmission also function as the sensing pattern, eliminating the need for separate sensing components
Solution Approach 2:
The patent merges the connection function and sensing function into a single integrated structure. The sensing pattern parts are formed by arranging conductive lines within the FPCB itself, combining the circuit board's structural role with its sensing role in one unified design
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 accurate folding angle detection, allowing the device to adjust its operating mode accordingly, enhancing functionality and usability.
Implementation Method 1
a sensor configured to identify an impedance in the FPCB; and a processor configured to identify a folding angle between the first housing and the second housing based on the impedance
Data Source
AI summary
A foldable electronic device includes a display including a first and second areas; a first and second housings; a hinge structure foldably connecting the first housing and the second housing to each other on a folding axis; a flexible printed circuit board (FPCB) extending across the folding axis from a first space between the first housing and the display to a second space between the second housing and the display and including a first bending portion and a second bending portion; a sensor configured to identify an impedance in the FPCB; and a processor configured to identify a folding angle between the first housing and the second housing based on the impedance. The first bending portion includes a first sensing pattern part including a first pattern forming a first electrical path and a second pattern forming a second electrical path.