Lid Magnetic Sensing Layout for Reliable Open-Closed Detection

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Solution Overview

Problem

Wireless device cases face challenges in reliably detecting the open or closed state due to interference from multiple magnets, leading to inefficient charging and potential damage to magnetic sensors, especially in compact designs where IATA regulations prohibit charging during transit and shipping.

Innovation Solution

A magnetic sensing device with a dual output unipolar Hall Effect sensor configuration, utilizing a first magnet at a fixed distance and a second and third magnet at adjustable distances, where different magnetic fields trigger distinct polarity outputs to reliably detect the case's open or closed state, reducing interference and energy wastage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple magnets are used for holding the case closed and detecting state, then the case can perform charging and other functions based on case state, but magnetic field interference occurs leading to unreliable sensor detection

Engineering Contradiction:
Improvecase state detection capabilityVSAvoidsensor detection reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The magnetic sensing system is segmented into multiple independent magnetic sensors, each dedicated to detecting the state of a specific magnet. This segmentation allows the system to distinguish between magnetic fields from different sources, preventing interference and enabling reliable detection of case state despite the presence of multiple magnets for holding and detection purposes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary processing layer that receives signals from multiple magnetic sensors and determines case state based on the combined information. This intermediary logic layer filters out magnetic field interference by analyzing patterns across multiple sensors, reliably distinguishing between magnets used for holding the case closed versus those used for state detection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If magnets are positioned close together in compact designs, then the device size is reduced, but magnetic field interference increases causing sensor saturation and potential damage

Engineering Contradiction:
Improvecase sizeVSAvoidmagnetic field interference
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The magnetic sensing system is segmented into multiple independent magnetic sensors, each dedicated to detecting the state of a specific magnet. This segmentation allows the system to distinguish between magnetic fields from different sources, preventing interference and enabling reliable detection of case state despite the presence of multiple magnets for holding and detection purposes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each magnetic sensor is configured with specific local sensitivity characteristics tailored to detect only its designated magnet's field. By optimizing the local detection parameters of each sensor, the system can operate reliably in compact configurations where magnets are positioned close together, as each sensor ignores fields from other magnets and focuses only on its target.

Inventive Principle:
Principle #3Local quality

3Productivity

If magnetic sensors continuously monitor case state for charging functions, then charging can be activated when case is opened, but energy is wasted during transit when charging should be prohibited

Engineering Contradiction:
Improvecharging function activationVSAvoidenergy wastage during transit
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The magnetic sensing system performs preliminary detection of case state changes and only activates charging functions when the case transitions from closed to open state. This preliminary action allows the system to prepare for charging activation without actually consuming charging energy during transit, thereby avoiding energy wastage while maintaining the capability to charge when needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors magnetic field signals from multiple sensors and uses feedback logic to determine whether the case is in transit or being used. By analyzing patterns in the magnetic field data, the system can distinguish between transit conditions (case closed for extended periods) and usage conditions (case opened), thereby controlling charging activation to avoid energy wastage during transit while enabling charging during normal use.

Inventive Principle:
Principle #23Feedback

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 reliable proximity detection, improves the out-of-box experience by ensuring wireless devices are charged upon initial opening, and conserves energy by accurately determining the case's state for charging functions without violating regulations, while reducing the number of required magnets for cost and manufacturing efficiency.

Implementation Method 1

A magnetic sensing device with a dual output unipolar Hall Effect sensor configuration

Methodology Applied
Scientific EffectHall Effect: Hall Effect

Data Source

PatentEP4235357A1Magnetic sensing device for lid
Publication Date: 2023.08.30 GOOGLE LLC
  • EP4235357A1 patent drawingFigure 1A
  • EP4235357A1 patent drawingFigure 1B
  • EP4235357A1 patent drawingFigure 2A

AI summary

The technology provides for a magnetic sensing device. The device includes a magnetic sensor configured to generate a first output triggered by a first polarity and a second output triggered by a second polarity. The device includes a first magnet, a second magnet, and a third magnet. The device may be configured such that, when the second magnet is not within a predetermined distance from the first magnet, a magnetic field from the first magnet having the first polarity causes the first output and the second output to have a first set of values. The device may be configured such that, when the second magnet is within the predetermined distance from the first magnet, a magnetic field from the third magnet having the second polarity causes the first output and the second output to have a second set of values.