Ambient Light Sensor Angular Detection via Concentric Strips

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Solution Overview

Problem

Designing ambient light sensors with angular detection capabilities for electronic devices is challenging due to interference from light-emitting components and electromagnetic interference, which affects the accuracy of ambient light measurements.

Innovation Solution

The electronic device incorporates an optical sensor with photodetectors and light control layers forming concentric strips of opaque material, including a diffuser and a color sensor, to compute angular information from ambient light readings, using control circuitry to correct for interference and improve measurement accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If ambient light sensors are incorporated into electronic devices, then the device can detect ambient light conditions, but light-emitting components and electromagnetic interference reduce measurement accuracy

Engineering Contradiction:
Improveambient light measurement accuracyVSAvoidinterference from light-emitting components and electromagnetic interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The sensor array is divided into multiple photodetectors arranged in specific geometric patterns (e.g., hexagonal, triangular configurations). Each photodetector captures light from different angular directions, and the control circuitry processes signals from multiple segments to compute angular information and eliminate interference through differential measurements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the sensor array have specialized functions: central photodetectors may measure direct ambient light while peripheral photodetectors detect light at different angles. The control circuitry applies different processing algorithms to signals from different regions to optimize measurement accuracy for specific angular ranges and interference conditions.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If angular detection capabilities are added to ambient light sensors, then the device can determine light angles for display adjustment and AR rendering, but the device complexity increases

Engineering Contradiction:
Improveangular detection capabilityVSAvoidsensor structure and control circuitry complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The same photodetector array and control circuitry serve multiple functions: measuring ambient light intensity, determining angle of incidence, and providing data for both display brightness adjustment and augmented reality virtual object rendering. This multi-functionality achieves angular detection capability without proportionally increasing device complexity.

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

Solution Approach 2:

The patent combines the ambient light sensor array with the display device structure, locating photodetectors in border regions or behind transparent portions of the display. The control circuitry integrates processing for both ambient light sensing and angular detection into a single system, reducing overall device complexity compared to separate systems.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If photodetectors are positioned under the display pixel array, then the sensor is integrated into the display structure, but light from the display interferes with ambient light measurements

Engineering Contradiction:
Improvesensor integration with displayVSAvoiddisplay light interference
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the ambient light sensing function from behind the entire display area and positions photodetectors specifically in border regions or transparent portions of the display where display light does not interfere. This selective positioning maintains integration ease while eliminating display light interference with ambient light measurements.

Inventive Principle:
Principle #2Taking out (Extraction)

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 enables accurate detection of ambient light angles, enhancing display brightness adjustment and virtual object rendering in augmented reality applications by reducing interference and improving angular resolution.

Implementation Method 1

The optical sensor can include one or more photodetectors

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

light control layers disposed over the one or more photodetectors and including light control structures forming concentric strips of opaque material

Methodology Applied
Scientific EffectLight Absorption: Absorption (EM radiation)

Data Source

PatentEP4421460A1Electronic devices with ambient light angular detection
Publication Date: 2024.08.28 APPLE INC
  • EP4421460A1 patent drawingFigure 1
  • EP4421460A1 patent drawingFigure 2
  • EP4421460A1 patent drawingFigure 3

AI summary

An electronic device may have an optical sensor such as an ambient light sensor for detecting ambient light. The ambient light sensor may include one or more photodetectors and light control layers disposed over the photodetectors. The light control layers may include light control structures forming concentric strips of opaque or light absorbing material. The light control layers may include one layer of light control structures, two layers of light control structures, or three or more layers of light control structures separated by one or more intervening transparent substrates. The electronic device may include associated control circuitry configured to compute angular information on the ambient light based on readings output from the one or more photodetectors.