Backlight 3D Camera Module for Full-Screen Displays

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Solution Overview

Problem

Existing full-screen display devices require a non-display area, such as a notch, to accommodate depth camera modules, which compromises aesthetics and full-screen experience due to the low optical power of Vertical Cavity Surface Emitting Lasers (VCSELs) used in traditional depth camera modules.

Innovation Solution

A 3D camera module is integrated into the display device with an edge-emitting laser and imaging module positioned at the backlight side of the display panel, allowing laser light to penetrate and re-penetrate the panel to capture depth images without the need for a non-display area, utilizing a high-output edge-emitting laser and beam splitting devices to enhance optical power and precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If VCSELs are used in traditional depth camera modules, then the device can be installed in a non-display area, but the optical power is insufficient and aesthetics are compromised

Engineering Contradiction:
Improveoptical powerVSAvoidaesthetics
Core Design Contradiction:
Illumination intensityVSShape

Solution Approach 1:

The patent changes the type of laser from VCSEL to edge-emitting laser, which fundamentally alters the emission characteristics and optical power output. This parameter change enables sufficient optical power to penetrate the display panel while eliminating the need for a non-display area, thus resolving the contradiction between illumination intensity and aesthetics

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent moves the depth camera module from a traditional front-facing position (requiring non-display area) to a backlight-side position. This dimensional relocation allows the module to utilize the display panel itself as the installation location, eliminating the aesthetic compromise while achieving sufficient optical power through the display

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If the drive current of the edge-emitting laser is increased to improve optical power, then penetration capability is enhanced, but total pulse energy increases which may exceed safety limits

Engineering Contradiction:
Improveoptical powerVSAvoidoptical power safety limit
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent employs pulse modulation of the edge-emitting laser, converting continuous high-power emission into periodic short pulses. This allows the peak optical power to be sufficiently high for display penetration while the duty cycle reduction keeps the average power and total pulse energy within safety limits for human eyes

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent dynamically adjusts the drive current and pulse width of the edge-emitting laser to optimize the balance between peak optical power and total energy output. By making the emission parameters variable rather than fixed, the system can achieve high penetration capability during the pulse while maintaining safety through controlled pulse duration and frequency

Inventive Principle:
Principle #15Dynamics

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 improves the aesthetics and full-screen experience by eliminating the need for a non-display area, enabling effective depth image capture even with low transmittance displays, while maintaining safe optical power levels for human eyes.

Implementation Method 1

the depth camera module comprises an edge-emitting laser and an imaging module; the edge-emitting laser is configured for emitting laser light to penetrate the display panel

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

the imaging module is configured for receiving laser light reflected by the object that re-penetrates the display panel

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

the beam splitting device is configured for splitting the laser light emitted by the edge-emitting laser into multiple randomly distributed laser beams

Methodology Applied
Scientific EffectBeam splitting:

Data Source

PatentEP3913914B1Display device having 3D camera module and electronic device
Publication Date: 2022.12.14 SHENZHEN GUANGJIAN TECH CO LTD
  • EP3913914B1 patent drawingFigure 1
  • EP3913914B1 patent drawingFigure 2
  • EP3913914B1 patent drawingFigure 3(a)~3(b)

AI summary

Display devices and electronic apparatuses with 3D camera modules are provided. An exemplary device comprises a display and a 3D camera module, wherein the 3D camera module comprises a depth camera module disposed at a backlight side of the display; the depth camera module comprises an edge-emitting laser and an imaging module; the edge-emitting laser is configured for emitting laser light, for the emitted laser light to penetrate the display to reach an object; and the imaging module is configured for receiving laser light reflected by the object that penetrates the display, and obtaining a depth image of the object based on the reflected laser light.