Inductive Proximity Sensor Polling Interval Control

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Solution Overview

Problem

Existing electronic devices with movable portions, such as mobile phones, face issues with mechanical proximity sensors wearing out due to frequent use and magnetic proximity sensors being affected by strong magnetic fields, leading to inaccurate position detection.

Innovation Solution

Implementing an electrically-activated inductive proximity sensor with a controller that adjusts polling intervals based on the device's activity state to balance power consumption and latency, using activity sensors to determine when to activate or deactivate the sensor, thereby reducing mechanical wear and magnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a mechanical proximity sensor is used to detect open/closed position, then the sensor requires little electrical power to function, but the sensor wears out and fails due to frequent use

Engineering Contradiction:

Improveelectrical power consumptionVSAvoidsensor durability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent replaces the mechanical proximity sensor with a magnetic proximity sensor (Hall Effect sensor) that has no mechanical moving components. This substitution eliminates wear and tear from mechanical contact while maintaining low power consumption, thereby resolving the contradiction between energy efficiency and sensor durability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent further replaces the magnetic proximity sensor with an inductive proximity sensor that uses electromagnetic fields to detect the position of the movable portion. This non-contact sensing method eliminates both mechanical wear and sensitivity to magnetic interference, providing a robust solution that maintains reliability while keeping power consumption low through selective activation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a magnetic proximity sensor is used to detect open/closed position, then the sensor requires little electrical power and has no mechanical moving components, but the sensor is affected by strong magnetic fields causing false detections

Engineering Contradiction:

Improvesensor reliabilityVSAvoidmagnetic field interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the magnetic proximity sensor with an inductive proximity sensor that detects the position of the movable portion through electromagnetic induction rather than magnetic field sensing. This substitution eliminates sensitivity to external magnetic fields while maintaining contactless operation, thereby resolving the contradiction between reliability and susceptibility to magnetic interference.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If the inductive proximity sensor is continuously activated to ensure accurate detection, then detection accuracy is maintained, but power consumption increases

Engineering Contradiction:

Improveposition detection accuracyVSAvoidsensor power consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic activation of the inductive proximity sensor based on the activity state of the electronic device. The controller activates the sensor only when the device is in an active state (e.g., screen on, device in use) and deactivates it during idle states, thereby maintaining detection accuracy when needed while significantly reducing overall power consumption.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent dynamically adjusts the operational state of the inductive proximity sensor based on real-time detection of device activity. The controller modifies the sensor's activation status according to whether the device is being used or is idle, creating a flexible system that balances measurement precision with energy efficiency according to actual operational requirements.

Inventive Principle:

Principle #15Dynamics

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 extends the lifespan of the sensor by reducing mechanical wear and improves accuracy by dynamically adjusting power usage and detection latency based on the device's activity state, ensuring reliable open/closed position sensing.

Implementation Method 1

an open/closed position sensor that detects an open/closed position of the movable portion

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS11157058B2Setting polling interval of open/closed position sensor for a movable portion of an electronic device based on activity state of the electronic device

Publication Date: 2021.10.26 MOTOROLA MOBILITY LLC

AI summary

An electronic device detects ambient contextual data and positioning data such as orientation and motion to determine an activity state of the electronic device. A controller sets a polling interval of an open/closed position sensor that is connected to a movable portion connected to a base to detect an open/closed event. In response to determining a first activity state, controller sets a first polling interval that mitigates power consumption. In response to determining a second activity state, the controller sets the polling interval to a second polling interval that is shorter than the first polling interval to reduce latency in detecting the open/closed event.