Wireless Charging Coil Positioning to Reduce Echo Signal Interference
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Solution Overview
Problem
Conventional wireless charging devices for portable terminals can erroneously detect the presence of a terminal due to echo signals from the charging coil, leading to incorrect operations when the charging coil's position overlaps with the position detection coils after charging is complete.
Innovation Solution
The wireless charging device moves the charging coil to a position where its center deviates from the center of any of the position detection coils after charging is completed, and adjusts the judgment level for echo signals to accurately determine the presence of a portable terminal on the placement plate, preventing erroneous operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the charging coil is positioned at the center of the placement plate for efficient charging, then charging efficiency is improved, but erroneous detection of terminal presence occurs due to echo signals from the charging coil
Solution Approach 1:
The placement plate is divided into multiple detection regions with separate position detection coils, allowing the system to distinguish between echo signals from the charging coil and actual terminal presence by comparing signals from different segments
Solution Approach 2:
Position detection coils are introduced as intermediary elements that mediate between the charging coil and the control unit, providing additional information to distinguish true terminal presence from echo signals
2Measurement precision
If position detection coils are used to detect terminal presence, then terminal positioning accuracy is improved, but false detection occurs when charging coil echo signals are mistaken for terminal signals
Solution Approach 1:
The system uses feedback from multiple position detection coils to continuously monitor and distinguish between echo signals and actual terminal presence, with the control unit adjusting detection thresholds based on charging coil activity
Solution Approach 2:
The detection threshold parameter is dynamically adjusted based on the charging state, raising the threshold during charging to filter out echo signals and lowering it when not charging to detect terminal presence
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 effectively reduces false detection of terminal presence by minimizing echo signals from the charging coil, ensuring accurate operation and preventing incorrect charging operations.
Implementation Method 1
Whether or not and at what position a portable terminal has been put on the placement plate are detected on the basis of whether or not echo signals return immediately thereafter from a charging coil incorporated in the portable terminal
Implementation Method 2
a charging coil which is disposed movably in the body case so as to be opposed to the bottom surface of the placement plate
Data Source
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AI summary
This wireless charging device is configured such that after charging of a portable terminal by a charging coil (8) is completed, a controller (10) drives motors (28, 33) to move the charging coil (8) to a position where the center of the charging coil deviates from the centers of multiple position detection coils (14Ba, 14Bb, 14Bc, 14Bd). As a result, echo signals from the charging coil (8) produced from pulse signals from the position detection coils (14Ba, 14Bb, 14Bc, 14Bd) become sufficiently weakened to less than a determination level, so erroneous operations can be prevented.