Touch sensor assembly and a refrigerator door including the same

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Solution Overview

Problem

Existing touch sensor assemblies for household appliances, such as refrigerators, face challenges in providing a reliable and durable touch interface on metal or glass surfaces while maintaining aesthetic appeal and preventing static electricity interference.

Innovation Solution

A touch sensor assembly is integrated into the door of a refrigerator, featuring a stainless steel front panel with a display window and touch operation unit, utilizing a touch booster and sensor PCB with elastic members to detect touch inputs and protect against static electricity, while ensuring the assembly is non-protrusive and aesthetically pleasing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a touch sensor assembly is integrated into a metal or glass surface, then the touch interface functionality is improved, but static electricity interference occurs

Engineering Contradiction:
Improvetouch interface functionalityVSAvoidstatic electricity interference
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A touch booster plate is introduced as an intermediary component between the metal/glass surface and the sensor. The touch booster plate is electrically connected to the sensor and acts as a mediator to detect touch input while preventing static electricity from reaching the sensor, thus resolving the contradiction between maintaining touch functionality and blocking static electricity interference

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the touch sensor assembly uses protruding components, then the sensor detection capability is improved, but the aesthetic appearance deteriorates

Engineering Contradiction:
Improvesensor detection capabilityVSAvoidaesthetic appearance
Core Design Contradiction:
Measurement precisionVSShape

Solution Approach 1:

The touch sensor assembly is designed to operate in a different dimensional plane, where the sensor elements are positioned behind the surface plane rather than protruding forward. This allows the detection functionality to operate effectively while maintaining a flush, aesthetically pleasing surface appearance

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Shape

If the touch sensor assembly is made non-protrusive, then the aesthetic appearance is improved, but the sensor detection sensitivity may deteriorate

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidsensor detection sensitivity
Core Design Contradiction:
ShapeVSMeasurement precision

Solution Approach 1:

The touch booster plate serves as an intermediary that extends the sensing capability without requiring the sensor itself to protrude. The booster plate can be positioned closer to the surface while the actual sensor remains recessed, thereby maintaining both aesthetic appearance and detection sensitivity

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution provides a reliable and durable touch interface that effectively detects user inputs while preventing static electricity interference, maintaining the appliance's aesthetic appeal and operational reliability.

Implementation Method 1

touch sensor assemblies are used for household appliances and may include electrostatic capacitance sensors

Methodology Applied
Scientific EffectElectrostatic capacitance: Capacitance

Data Source

PatentEP3037758B1Touch sensor assembly and a refrigerator door including the same
Publication Date: 2021.06.16 LG ELECTRONICS INC
  • EP3037758B1 patent drawingFigure 1
  • EP3037758B1 patent drawingFigure 2
  • EP3037758B1 patent drawingFigure 3

AI summary

In a sensor assembly (500), a hole-shaped sensor support portion (713) is formed at a sensor printed circuit board (PCB) (700), a touch sensor (750) is disposed at the sensor support portion (713), and an elastic member (720) is installed at a rear surface of the sensor PCB (700).In addition, a sensor assembly (500) according to an embodiment of the present invention may include a sensor PCB (700) having a copper coating film (712) which constitutes a circuit printed on a top surface of a plastic material (717), a touch sensor (750) seated on a sensor support portion (713) formed at the sensor PCB (700), and a cover member (770) which is attached onto a rear surface of the sensor PCB (700) and covers the sensor support portion (713).