Display Depth Sensing via Frequency-Division Multiplexed Light Sources

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Solution Overview

Problem

The integration of depth cameras with display screens is hindered by the large size of silicon-based image sensors, making miniaturization difficult and interfering with accurate depth image acquisition due to sensor interference and ambient light interference, which complicates high-precision spatial interaction in applications like 3D displays and virtual/augmented reality.

Innovation Solution

A display device with multiple light source groups and image sensor groups, each emitting and receiving light of distinct frequencies to avoid interference, allowing for accurate depth image information acquisition and high-precision spatial interaction by controlling light source and sensor groups to work simultaneously.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If silicon-based image sensors are used for depth camera integration, then depth image acquisition capability is improved, but device size increases and miniaturization becomes difficult

Engineering Contradiction:
Improvedepth image acquisition capabilityVSAvoidsensor size
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The patent changes the fundamental parameter of the image sensor from silicon-based to organic photodetector-based, enabling miniaturization while maintaining depth sensing capability. This material parameter change allows the sensor to achieve comparable performance with significantly reduced size.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs organic photodetectors that can be manufactured using low-cost solution processing methods, replacing expensive silicon-based sensors. This enables mass production of miniaturized depth cameras at lower cost, facilitating integration with display screens.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Adaptability or versatility

If multiple sensors are integrated with display screens, then functionality is improved, but sensor interference and ambient light interference increase

Engineering Contradiction:
Improveintegration functionalityVSAvoidsensor interference and ambient light interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies wavelength-selective filtering at each sensor location, where each organic photodetector group is paired with specific wavelength filters to detect only designated wavelengths. This local quality control eliminates cross-talk between adjacent sensors and rejects ambient light, enabling high-precision depth sensing despite dense integration with display pixels.

Inventive Principle:
Principle #3Local quality

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 enables the display device to obtain accurate depth image information efficiently, facilitating high-precision spatial interaction and reducing the time required for depth image acquisition, thus improving detection efficiency.

Implementation Method 1

a first light source group is configured to emit light of a first set frequency to a display side of the display device to illuminate a first partial region of a detection object

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Implementation Method 2

driving a first image sensor group to receive the light of the first set frequency emitted by the first light source group and reflected by the detection object

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Implementation Method 3

receive the light of the first set frequency emitted by the first light source group and reflected by the detection object

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3958247B1Display apparatus, electronic device, and driving method of display apparatus
Publication Date: 2023.12.13 BOE TECHNOLOGY GROUP CO LTD
  • EP3958247B1 patent drawingFigure 1~2
  • EP3958247B1 patent drawingFigure 3A~3B
  • EP3958247B1 patent drawingFigure 4~5A

AI summary

A display device, an electronic equipment, and a method for driving a display device are disclosed. The display device (20) includes a first light source group (110), a second light source group (120), a first image sensor group (210), and a second image sensor group (220). The first light source group (110) is configured to emit light of a first set frequency (f1) to a display side of the display device (20) to illuminate a first partial region of a detection object (10), the second light source group (120) is configured to emit light of a second set frequency (f2) to the display side of the display device (20) to illuminate a second partial region of the detection object (10), and the first set frequency (f1) is different from the second set frequency (f2). The first image sensor group (210) is configured to receive the light of the first set frequency (f1) emitted by the first light source group (110) and reflected by the detection object (10), and the second image sensor group (220) is configured to receive the light of the second set frequency (f2) emitted by the second light source group (120) and reflected by the detection object (10).