Screen Leakage Light Drop Depth Determination for Under-Display Sensors

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Solution Overview

Problem

Accurate ambient light detection in electronic equipment is hindered by screen leakage light, which affects the accuracy of ambient light detection due to its influence on the signal-to-noise ratio and environmental complexities.

Innovation Solution

A method and device that determine the drop depth of screen leakage light by obtaining sampling data based on a vertical synchronization signal, filtering it according to signal-to-noise ratio requirements, and categorizing it into different sampling sequences to calculate the drop depth, thereby isolating the impact of screen leakage light from ambient light detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If ambient light detection is performed using under-screen optical sensors, then the user experience is improved with full-screen displays, but the detection accuracy deteriorates due to screen leakage light interference

Engineering Contradiction:

Improvefull-screen display capabilityVSAvoidambient light detection accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent segments the detected light signal into two distinct components: screen leakage light and ambient light. By separating these overlapping signals through waveform analysis during different screen states (on/off), the system can independently measure and subtract the screen leakage component, thereby recovering accurate ambient light detection despite the presence of full-screen display requirements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces screen on/off state transitions as an intermediary mechanism to separate the mixed light signals. By controlling the screen to switch states and measuring the optical sensor output during each state, the system creates distinct measurement conditions that allow mathematical separation of screen leakage and ambient light components, resolving the accuracy issue while maintaining full-screen display capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If screen leakage light is not eliminated, then the device complexity is reduced, but the ambient light detection accuracy deteriorates

Engineering Contradiction:

Improveoptical sensor system structureVSAvoidambient light detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent makes the optical sensor system self-service by using its own measurements during screen on/off transitions to automatically characterize and compensate for screen leakage light. The system performs self-calibration by measuring the sensor output when the screen is off (pure ambient light) and when the screen is on (ambient light plus screen leakage), then uses these measurements to calculate and remove the screen leakage component from subsequent readings, eliminating the need for additional hardware.

Inventive Principle:

Principle #25Self-service

3Ease of operation

If sampling is performed without synchronization to vertical sync signal, then the ease of operation is improved, but the measurement precision deteriorates due to noise from ambient light strobing

Engineering Contradiction:

Improvesampling process simplicityVSAvoiddrop depth calculation accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements periodic sampling synchronized to the vertical sync signal, which governs the screen's refresh cycle. By sampling at regular intervals aligned with the screen's natural periodic operation, the system captures consistent waveform patterns that represent true screen leakage characteristics, while asynchronous sampling during ambient light strobing would capture random noise. This periodic synchronization improves measurement precision while maintaining operational simplicity through automatic sync signal detection.

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 approach enhances the accuracy and reliability of ambient light detection by reducing noise and distortion, improving the signal-to-noise ratio, and adapting to various environmental conditions.

Implementation Method 1

Under-screen optical sensors can detect the ambient light of the environment in which the electronic equipment is located

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS20250022441A1Method, device, and electronic equipment for determining the drop depth of screen leakage light

Publication Date: 2025.01.16 SHENZHEN GOODIX TECH CO LTD

AI summary

A method, a device and an electronic equipment for determining the drop depth of screen leakage light, the method comprising: obtaining a sampling data based on a vertical synchronization signal; determining a first sampling sequence, as well as a second sampling sequence and/or a third sampling sequence based on the sampling data, the first sampling sequence is the sampling sequence of the drop zone of the screen leakage light drop waveform, the second sampling sequence is the sampling sequence on the left side of the drop zone of the screen leakage light drop waveform, and the third sampling sequence is the sampling sequence on the right side of the drop zone of the screen leakage light drop waveform; determining the drop depth based on the first sampling sequence, as well as the second sampling sequence and/or the third sampling sequence.