Segmented Shield Case for Contactless Power Transmission Noise Reduction
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Solution Overview
Problem
Existing contactless power transmission devices face challenges in reducing radiation noise effectively due to noise sources in the power transmission and reception circuits, with existing shielding techniques either failing to adequately reduce electromagnetic field leakage or complicating the shield structure, making it difficult to extract and insert power reception devices efficiently.
Innovation Solution
A contactless power transmission device with a shield case partitioned into multiple shield rooms and equipped with notches on the side surfaces and partitioning plates, allowing for easy extraction and insertion of power reception devices while reducing radiation noise by minimizing the opening area and utilizing a shield structure that effectively cancels electromagnetic waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a shield box is provided to the power transmission coil and power reception coil, then shielding effect is improved, but radiation noise from transmission path leakage is not sufficiently reduced
Solution Approach 1:
The shield case is divided into multiple shield rooms (first shield room, second shield room, third shield room) separated by partitioning plates. Each shield room contains specific components (power transmission circuit, power reception circuit, coils) to segment electromagnetic fields and reduce leakage through strategic positioning of notches on partitioning plates
Solution Approach 2:
Conductive plates are used as intermediary elements to connect partitioning plates to the shield case, creating continuous shielding paths. These conductive plates act as mediators to ensure electromagnetic compatibility between separated shield rooms while maintaining overall shielding effectiveness
2Object-affected harmful factors
If a large-sized shield is provided to cover the outer side of shields, then radiation noise is reduced, but device complexity and size are increased
Solution Approach 1:
Instead of using one large external shield, the invention segments the shielding function into multiple internal shield rooms with partitioning plates. Each partitioning plate has notches positioned to control electromagnetic field leakage, achieving comprehensive noise reduction through distributed segmentation rather than a single large structure
Solution Approach 2:
The shielding approach transitions from external coverage (adding size in outer dimensions) to internal segmentation (utilizing three-dimensional space within the shield case). Partitioning plates divide the internal volume into functional zones, reducing radiation noise through spatial arrangement rather than external expansion
3Object-affected harmful factors
If opening area of shield case is minimized, then radiation noise is reduced, but ease of operation for extraction and insertion is worsened
Solution Approach 1:
The shield case has a minimal overall opening area for reduced radiation noise, but partitioning plates within the shield case have notches that provide localized access points. These notches allow fingers to engage with the power reception device for easy extraction and insertion without requiring larger openings that would compromise shielding effectiveness
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
The proposed solution significantly reduces radiation noise and facilitates easy extraction and insertion of power reception devices, enhancing the device's suitability for portable equipment by improving shielding efficiency without increasing the shield's size or complexity.
Implementation Method 1
a shield case 40 which has an opening portion 41 at one end portion thereof, and is partitioned into a plurality of shield rooms 40A to 40C by partitioning plates 51 and 52
Implementation Method 2
A contactless power transmission device is an apparatus which transmits power to a power reception device such as a portable terminal or a tablet terminal by using electromagnetic coupling such as electromagnetic induction or magnetic field resonance
Implementation Method 3
a resonance circuit 211 configured of the power reception coil 21 and a resonance capacitor 22
Data Source
AI summary
A contactless power transmission device transmits power to a power reception device in a contactless manner, and includes a shield case which has an opening portion at one end portion thereof, and is partitioned into a plurality of shield rooms by partitioning plates; a power transmission circuit which is for transmitting power and is disposed to correspond to each of the plurality of shield rooms; a plurality of power transmission coils which are disposed on the inner side in the plurality of shield rooms and transmit AC power from the power transmission circuit to the power reception device; and a notch which is formed on side surfaces of the shield case or the partitioning plates, from the opening portion toward the inner side such that both sides of a rear end portion of the power reception device inserted into the plurality of shield rooms can be held.