Mobile Terminal Light Sensor Polarization Segmentation

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Solution Overview

Problem

Full-screen mobile terminals face challenges in improving screen-to-body ratio due to light leaks from optical sensing devices like range sensors and cameras, which affect detection accuracy.

Innovation Solution

A mobile terminal design incorporating a light sensor with N first regions and M second regions, each with specific polarizing components and photodetectors, where the polarization directions are parallel and perpendicular respectively, allowing for accurate detection of ambient light and light emitted by the display panel, and enabling the elimination of light emission influence on ambient light detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the light sensor is arranged below the screen to improve screen-to-body ratio, then the screen-to-body ratio is improved, but the light sensor is affected by light leak from the screen leading to inaccurate detection results

Engineering Contradiction:
Improvescreen-to-body ratioVSAvoidlight detection accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The light sensor is divided into multiple regions (first regions and second regions) with different polarizing components. The first regions have second polarizing components with polarization direction parallel to the first polarizing component, while the second regions have third polarizing components with polarization direction perpendicular to the first polarizing component. This segmentation allows different regions to detect different light components, enabling separation of ambient light detection from display panel light leakage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the light sensor are assigned different polarizing component configurations tailored to their specific detection functions. The first regions use polarizing components oriented parallel to the first polarizing component for detecting ambient light, while the second regions use polarizing components oriented perpendicular for detecting display panel light. This local differentiation of properties enables precise selective detection.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If polarizing components are added to separate light detection, then detection accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvelight detection accuracyVSAvoidsensor structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple polarizing components (first polarizing component, second polarizing components, third polarizing components) and photodetector regions are integrated into a single light sensor structure. The first regions with second polarizing components and the second regions with third polarizing components are combined in one sensor array, allowing simultaneous detection of both ambient light and display panel light through a unified structural design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The light sensor is designed as a multi-functional device that can simultaneously detect both ambient light intensity and display panel light emission. By incorporating multiple polarizing components with different orientations and multiple photodetector regions, the single sensor performs both functions that were previously required separate sensors, reducing overall system complexity despite the internal complexity of the sensor itself.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 design enhances detection accuracy by separating the detection of ambient light and light emitted by the display panel, improving the screen-to-body ratio and reducing structural complexity, leading to more precise light intensity information for automatic backlight adjustment.

Implementation Method 1

the ambient light having passed through the first polarizing component is linearly polarized light

Methodology Applied
Scientific EffectPolarisation: Polarisation

Implementation Method 2

a polarization direction of the second polarizing component is parallel to that of the first polarizing component

Methodology Applied
Scientific EffectPolarisation: Polarisation

Implementation Method 3

a polarization direction of the second polarizing component is perpendicular to that of the third polarizing component

Methodology Applied
Scientific EffectPolarisation: Polarisation

Implementation Method 4

K photodetectors arranged in an array, and the second polarizing component is located above the K photodetectors

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP3805715B1Mobile terminal
Publication Date: 2023.08.23 BEIJING XIAOMI MOBILE SOFTWARE CO LTD

AI summary

A mobile terminal comprises a display panel, a light sensor and a first polarizing component. The display panel is between the first polarizing component and the light sensor. The ambient light having passed through the first polarizing component is linear polarized light. The light sensor comprises N first regions and M second regions, the total area of the N first regions is equal to that of the M second regions. Each of the first regions comprises a second polarizing component and K photodetectors. The second polarizing component is located above the K photodetectors. Each of the second regions comprises a third polarizing component and L photodetectors. The third polarizing component is located above the L photodetectors. The polarization direction of the second polarizing component is parallel to that of the first polarizing component. The polarization direction of the second polarizing component is perpendicular to that of the third polarizing component.