Under-Display Proximity Sensor Infrared Flicker Control

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Solution Overview

Problem

The proximity sensor in full-screen mobile phones, when disposed under the display screen, causes electron transfer due to emitted infrared light, leading to local flicker phenomena that degrade user experience by interfering with the normal display.

Innovation Solution

The electronic device incorporates a proximity sensor that emits and receives infrared light through a transparent display layer and a first coating layer, which transmits infrared light while blocking visible light, ensuring the sensor's operation without affecting the display, and includes a light shielding layer to prevent light leakage, allowing the sensor to be invisible externally.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the proximity sensor is disposed under the display screen to increase screen-to-body ratio, then the screen-to-body ratio is improved, but the display screen exhibits local flicker phenomenon due to electron transfer caused by infrared light emission

Engineering Contradiction:
Improvescreen-to-body ratioVSAvoidflicker phenomenon
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The proximity sensor emits infrared light in periodic pulses rather than continuously. The controller activates the proximity sensor to emit infrared light only during specific time intervals (first time interval and second time interval alternately), preventing continuous electron transfer and flicker while still enabling effective proximity detection through periodic measurement cycles.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts the operating state of the proximity sensor based on display screen status. When the display screen is in the first state (displaying content), the proximity sensor is activated to emit infrared light; when in the second state, emission is suspended. This dynamic coordination eliminates flicker while maintaining detection functionality.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If the proximity sensor emits infrared light continuously for detection, then the detection accuracy is improved, but the power consumption increases and flicker phenomenon occurs

Engineering Contradiction:
Improvedetection accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The proximity sensor operates in periodic pulse mode rather than continuous emission. The controller activates the sensor to emit infrared light only during designated time intervals, then suspends emission during other intervals. This periodic operation maintains detection accuracy through regular measurement cycles while significantly reducing power consumption compared to continuous emission.

Inventive Principle:
Principle #19Periodic action

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 configuration prevents the flicker phenomenon, enhances user experience by maintaining normal display operation, and optimizes power consumption by controlling the screen state based on proximity sensor data.

Implementation Method 1

a proximity sensor is disposed below a display screen. However, since the proximity sensor emits infrared light continuously during working for detecting a distance between an object outside the mobile phone and the mobile phone

Methodology Applied
Scientific EffectInfrared light emission and detection: Infrared Radiation

Implementation Method 2

a first coating layer, which transmits infrared light while blocking visible light

Methodology Applied
Scientific EffectSelective light absorption and transmission: Absorption (EM radiation)

Implementation Method 3

the infrared light easily causes electron transfer to occur in components in the display screen, resulting in local flicker phenomenon on the display screen

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3582089B1Control method, control device, electronic device and storage medium
Publication Date: 2023.08.23 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD

AI summary

The present disclosure provides a control method of an electronic device (100). The electronic device (100) includes a touch display screen (103) and a proximity sensor (16). The proximity sensor (16) is disposed under a display area (13) of the touch display screen (103). The control method includes: keeping (S02) the proximity sensor (16) deactivated; determining (S03) whether the touch display screen (103) is shielded according to a signal output by the touch display screen (103); controlling (S04) the touch display screen (103) to enter a black-out state and activating (S04) the proximity sensor (16) when the touch display screen (103) is shielded; and controlling (S05) a display state of the touch display screen (103) according to detection data of the proximity sensor (16). The present disclosure also provides a control device (2000), an electronic device (100), a storage medium and a computer device.