Infrared Proximity Sensor Threshold Adjustment for Lens Degradation

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Solution Overview

Problem

Infrared proximity sensors in mobile phones often misjudge light blocking due to reduced light transmittance through lenses affected by dust or abrasion, leading to frequent touchscreen toggling during calls.

Innovation Solution

A method to adjust the sensing threshold of infrared proximity sensors by measuring and comparing reflected infrared ray intensity values to pre-stored values, modifying the threshold when a significant difference is detected, thereby correcting for reduced light transmittance without hardware changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sensing threshold is set based on initial calibration, then the proximity sensor works accurately at first, but over time dust accumulation and lens abrasion reduce light transmittance causing false blocking detections

Engineering Contradiction:
Improveproximity sensing accuracyVSAvoidsensor performance duration
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The system performs preliminary calibration to establish baseline infrared ray intensity values when the lens is clean. These baseline values are stored and used for future comparisons to detect changes in light transmittance caused by dust or abrasion, enabling proactive threshold adjustment before false detections occur

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors reflected infrared ray intensity values and compares them against baseline values. When a significant difference is detected indicating lens degradation, the sensing threshold is automatically adjusted to compensate, creating a closed-loop feedback mechanism that maintains accuracy over time

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If the sensing threshold remains fixed, then the device structure is simple, but the sensor cannot adapt to changing environmental conditions and lens degradation

Engineering Contradiction:
Improvethreshold adaptabilityVSAvoidthreshold adjustment mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system dynamically changes the sensing threshold parameter based on detected changes in infrared ray intensity. By comparing current measurements with baseline values and calculating differences, the system adjusts the threshold to compensate for lens degradation, transforming a static parameter into an adaptive one without complex mechanical adjustments

Inventive Principle:
Principle #35Parameter changes

3Reliability

If hardware components are replaced to maintain performance, then sensing accuracy is restored, but the repair cost and complexity increase

Engineering Contradiction:
Improvesensing accuracyVSAvoidsensor maintenance
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The system performs self-diagnosis by monitoring infrared ray intensity changes and automatically adjusts its own sensing threshold to compensate for lens degradation. This self-service capability eliminates the need for manual intervention or hardware replacement, allowing the sensor to maintain accuracy throughout its service life

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces potential mechanical hardware solutions (lens cleaning mechanisms, component replacement) with an electronic/software-based solution. By using software algorithms to detect and compensate for physical degradation, the system avoids complex mechanical repair mechanisms

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 approach automatically repairs the proximity sensing function by adjusting the sensing threshold, preventing false blocking detections and maintaining accurate touchscreen control.

Implementation Method 1

The infrared proximity sensor can measure a reflected infrared ray intensity

Methodology Applied
Scientific EffectInfrared radiation detection: Infrared Radiation

Implementation Method 2

measure a reflected infrared ray intensity

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2713586B1Method and device for adjusting detecting threshold of infrared proximity sensor
Publication Date: 2017.05.03 HUAWEI DEVICE CO LTD
  • EP2713586B1 patent drawingFigure 1
  • EP2713586B1 patent drawingFigure 2
  • EP2713586B1 patent drawingFigure 3

AI summary

A method and an apparatus for adjusting a sensing threshold of an infrared proximity sensor are provided, and belong to the field of electronic technologies. The method includes: obtaining, through the infrared proximity sensor, a reflected infrared ray intensity value in an environment of a current light intensity; comparing the obtained reflected infrared ray intensity value with a pre-stored reflected infrared ray intensity value, so as to obtain a first difference; and when the first difference is greater than a preset first threshold, modifying the sensing threshold. A reflected infrared ray intensity value is pre-stored in a mobile phone, a reflected infrared ray intensity value in the environment of the current light intensity is obtained, then the obtained reflected infrared ray intensity value is compared with the pre-stored reflected infrared ray intensity value to determine whether the infrared proximity sensor misjudges blocking of the mobile phone because a light transmittance of a lens is reduced, and the fault is solved by modifying the sensing threshold, so that a proximity sensing function of the mobile phone can be automatically repaired without changing hardware.