Laundry Drum Dryness Sensing Using Wireless Power Transmission

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Solution Overview

Problem

Existing laundry processing apparatuses face challenges in accurately sensing the dryness level of laundry due to difficulties in powering dryness level sensors within the drum, which requires complex cable connections that are hard to maintain, especially with the drum's rotation.

Innovation Solution

The implementation of a wireless power transmission system, where a wireless power transmitter outside the drum supplies power to a wireless power receiver inside the drum, allowing the dryness level sensing device to operate without the need for cables or terminals, thus simplifying the configuration and reducing manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a dryness level sensor is implemented in the drum to directly contact the laundry, then the dryness level sensing accuracy is improved, but the device complexity increases due to the need for cable connections between the rotating drum and outside

Engineering Contradiction:
Improvedryness level sensing accuracyVSAvoidcable connection complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical cable connection system with a wireless power transmission system. A wireless power transmitter is disposed in the drum and a wireless power receiver is disposed in the lifter, enabling power supply without physical cable connections. This substitution eliminates the mechanical complexity of maintaining cable connections during drum rotation while maintaining the sensor's ability to directly contact laundry for accurate dryness sensing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Use of energy by moving object

If cables or terminals are used to supply power to the dryness level sensor in the rotating drum, then the sensor can be powered, but the ease of manufacture deteriorates due to the difficulty of connecting rotating and stationary parts

Engineering Contradiction:
Improvepower supply to sensorVSAvoidmanufacturing complexity
Core Design Contradiction:
Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The patent eliminates the mechanical cable connection system and replaces it with a wireless power transmission system. The wireless power transmitter in the drum and receiver in the lifter enable power supply without physical connections, dramatically simplifying the manufacturing process by removing the need to create reliable electrical connections between rotating and stationary components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Use of energy by moving object

If additional components like insulating band, metal band, and brush are implemented to supply power to the sensor, then the sensor can operate inside the drum, but the device complexity increases and the ease of repair worsens due to wear and contact force reduction

Engineering Contradiction:
Improvepower supply capabilityVSAvoidmaintenance difficulty
Core Design Contradiction:
Use of energy by moving objectVSEase of repair

Solution Approach 1:

The patent replaces the mechanical contact-based power supply system (brush and metal band) with a wireless power transmission system. This eliminates components subject to wear and contact force degradation, removing maintenance issues related to brush abrasion and contact reliability, thereby significantly improving ease of repair and reducing operational complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 enables more accurate dryness level sensing by positioning the dryness level sensor optimally within the drum and eliminates the need for complex cable connections, reducing manufacturing difficulties and saving parts.

Implementation Method 1

a wireless power transmitter outside the drum supplies power to a wireless power receiver inside the drum

Methodology Applied
Scientific EffectWireless power transmission: Electromagnetic Induction

Data Source

PatentEP3913127B1Laundry apparatus
Publication Date: 2025.06.04 LG ELECTRONICS INC
  • EP3913127B1 patent drawingFigure 1
  • EP3913127B1 patent drawingFigure 2
  • EP3913127B1 patent drawingFigure 3~4

AI summary

A laundry processing apparatus according to an embodiment of the present disclosure includes a drum rotatably disposed in a main body, a drive motor configured to provide rotational power to the drum, a lifter mounted on an inner circumferential surface of the drum, a dryness level sensing device provided in the lifter, a wireless power receiver electrically connected to the dryness level sensing device and provided in the lifter, a wireless power transmitter disposed between the main body and the drum to correspond to the wireless power receiver, and a controller configured to receive a sensing result from the dryness level sensing device and calculate a dryness level based on the received sensing result.