Backlight Control Using Angle and Infrared Intensity

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Solution Overview

Problem

Existing display screen backlight control systems using infrared proximity sensors inaccurately adjust the backlight state when an aperture is covered by a dark object, leading to incorrect power consumption management and user experience issues.

Innovation Solution

A method and apparatus that determine the included angle between a device and a preset direction, combined with infrared light intensity thresholds, to accurately control the display screen backlight during calls, preventing misoperations by considering both the angle and object presence near the aperture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the backlight control system uses only infrared light intensity thresholds, then the control logic is simple, but the measurement precision deteriorates when dark objects cover the aperture

Engineering Contradiction:
Improvecontrol logic complexityVSAvoidobject detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces a new dimension of measurement by detecting the included angle between the aperture and the normal direction of the display screen. This angular information complements the infrared light intensity measurement, allowing the system to distinguish between dark objects covering the aperture and normal proximity conditions. The control logic now considers both the angle parameter and intensity threshold, resolving the measurement precision issue without significantly increasing system complexity.

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

2Use of energy by moving object

If the system turns on the backlight when infrared intensity is low, then power consumption increases, but the reliability of the control system improves

Engineering Contradiction:
Improvepower consumptionVSAvoidbacklight control accuracy
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system uses feedback from the included angle detection to adjust the backlight control decision. When the aperture is covered by a dark object, the detected angle provides feedback that prevents erroneous backlight on-state decisions, even when infrared intensity is low. This feedback mechanism ensures reliable control by cross-validating the angle information with intensity data before making backlight state changes.

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

Improves the accuracy of backlight adjustments, enhancing user experience and reducing power consumption by accurately distinguishing between object presence and absence near the aperture, even when dark objects are involved.

Implementation Method 1

an infrared emitting diode (Infrared Emitting Diode, IR LED for short) and an infrared receiver. An IR LED 11 emits infrared light through an aperture 12

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 2

An infrared receiver 13 receives infrared light that is outside the aperture 12 and that is reflected by an object

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

the light emitted by the IR LED is absorbed by the dark object because the dark object has a strong capability of absorbing the light

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentEP3425890B1Method and apparatus for controlling backlight of display screen, electronic device and storage medium
Publication Date: 2020.12.30 HUAWEI TECH CO LTD
  • EP3425890B1 patent drawingFigure 1~2
  • EP3425890B1 patent drawingFigure 3~4
  • EP3425890B1 patent drawingFigure 5~6

AI summary

Embodiments of the present disclosure provide a method, an apparatus, and an electronic device for controlling a display screen backlight, and a storage medium. In the method, it is determined, with reference to an included angle between the electronic device and a preset direction and whether there is an object shielding an aperture in a call state, that the display screen backlight is adjusted to be on or off. The display screen backlight can be accurately adjusted to be on or off even in a scenario that the aperture is covered by dark hair.