Refrigerator Door Position Sensing for Automatic Lighting Control

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Solution Overview

Problem

Refrigerated wine display cabinets with transparent doors face challenges in user convenience for controlling internal lights, especially when integrated with automatic door opening systems, leading to energy inefficiency and bulb life issues.

Innovation Solution

A refrigerator with a position sensor and control device that activates internal lights and opens the door based on user interaction with the door, using a simple push or pull action, integrating seamlessly with automatic opening systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a dedicated control on the user interface is used to switch on internal lights, then the lighting control function is provided, but the user convenience deteriorates due to the interface being positioned near the roof which is not always easy to reach

Engineering Contradiction:
Improveuser convenience for lighting controlVSAvoidcontrol system arrangement
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The lighting control function is extracted from the roof-mounted user interface and relocated to the door. The door itself becomes the control element through integration of a position sensor that detects door movement, eliminating the need for users to reach the roof interface for lighting control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The door acts as an intermediary between the user and the lighting system. By detecting door position changes, the door mediates the control signal to activate or deactivate lights, providing a more accessible control mechanism without requiring direct interaction with the roof interface.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the internal lights are left on due to inconvenient control, then the lighting function is continuously available, but energy consumption increases and bulb life decreases

Engineering Contradiction:
Improvelighting control accessibilityVSAvoidenergy consumption of internal lights
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The lighting system operates periodically based on door opening events rather than remaining continuously on. The position sensor detects when the door is opened, triggering light activation only during these periodic intervals when illumination is actually needed, thereby reducing overall energy consumption.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The position sensor provides feedback about door position to the control device, which then adjusts lighting operation accordingly. This feedback mechanism ensures lights are activated only when the door is opened and deactivated when the door is closed, optimizing energy usage based on actual operational needs.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If an automatic door opening system is integrated, then door opening convenience is improved, but the lighting control becomes more complex requiring different controls for push-to-open and pull-to-open

Engineering Contradiction:
Improvedoor opening convenienceVSAvoidcontrol system integration
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The door position sensor serves multiple functions: it controls both the automatic door opening system and the internal lighting system. This universal control mechanism eliminates the need for separate controls for different door opening modes, as the same position detection system manages both functions adaptively.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The lighting control and automatic door opening control are merged into a single integrated system. The position sensor and control device work together to manage both door actuation and lighting activation, simplifying the overall control architecture despite the multiple functions performed.

Inventive Principle:
Principle #5Merging (Combining)

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

Provides convenient and energy-efficient lighting control, enhancing user experience and reducing energy consumption by integrating light activation with door operation.

Implementation Method 1

a position sensor configured to detect current positions of a reference portion of the door relative to a reference portion of the main body

Methodology Applied
Scientific EffectPosition sensing:

Data Source

PatentEP4636341A1Refrigerator with automatic lighting and method for controlling the automatic lighting of a refrigerator
Publication Date: 2025.10.22 SMEG
  • EP4636341A1 patent drawingFigure 1~2
  • EP4636341A1 patent drawingFigure 3
  • EP4636341A1 patent drawingFigure 4~5

AI summary

A refrigerator comprises: • a main body (2) provided with a cooling chamber (6); • a door (3) hinged to the main body (2) and movable between a stationary closed position, in which the door (3) closes the cooling chamber (6), and a fully open position; the door (3) being provided with at least one transparent portion (3a); • a position sensor (9) configured to detect current positions (Pci) of a reference portion (15) of the door (3) relative to a reference portion (16) of the main body (2); • a lighting system (5) comprising at least one light source (11) arranged within the chamber (6); • a control device (10), configured to activate the at least one light source (11) in response to a command (CA) given by a user on the door (3); the control device (10) being configured to activate the at least one light source (11) when the variation of the current position (ΔP) with respect to a reference position (RIF) is greater, in absolute value, than an activation threshold (ATT).