Under-screen Camera Optical Path Correction via Refractive Index Matching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The complex pixel structure in display screens causes diffraction interference during under-screen imaging, reducing the quality of images captured by camera modules in electronic devices.

Innovation Solution

Incorporating a pixel definition layer with organic light emitters and a filling layer having a refractive index difference smaller than that between the pixel definition layer and vacuum, which minimizes optical path differences and improves imaging quality by reducing diffraction interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the camera module is arranged under the display screen to achieve under-screen imaging, then the screen-to-body ratio is increased, but the complex pixel structure causes diffraction interference that reduces imaging quality

Engineering Contradiction:
Improvescreen-to-body ratioVSAvoidimaging quality
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The patent introduces a filling layer as an intermediary substance between the pixel definition layer and the camera module. This filling layer has a refractive index that is closer to the pixel definition layer than vacuum is, thereby serving as an optical mediator that reduces diffraction interference and improves light transmission quality from the display screen to the camera module underneath

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the optical parameter (refractive index) of the medium between the pixel definition layer and the camera module by introducing a filling layer with specific refractive index properties. This parameter change reduces the optical path difference and minimizes diffraction effects, thereby improving imaging quality while maintaining the under-screen camera configuration

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If a filling layer with refractive index closer to the pixel definition layer is introduced, then diffraction interference is reduced and imaging quality is improved, but the device structure becomes more complex

Engineering Contradiction:
Improveimaging qualityVSAvoiddisplay structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The filling layer is applied locally only in the regions where pixel holes are present, rather than uniformly across the entire display structure. This localized application optimizes optical performance specifically where needed (at the pixel openings where diffraction occurs) while minimizing the overall structural complexity and material usage

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 configuration enhances the quality of under-screen imaging by minimizing optical path differences and diffraction interference, leading to improved image acquisition through the display apparatus.

Implementation Method 1

a difference between refractive indices of the pixel definition layer and each of the plurality of filling members is smaller than a difference between refractive indices of the pixel definition layer and vacuum

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

the complex pixel structure will cause diffraction interference during imaging of the camera module, thereby reducing a quality of under-screen imaging

Methodology Applied
Scientific EffectDiffraction: Diffraction

Data Source

PatentEP3907556B1Electronic device and display apparatus
Publication Date: 2024.04.03 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP3907556B1 patent drawingFigure 1~2
  • EP3907556B1 patent drawingFigure 3~4
  • EP3907556B1 patent drawingFigure 5~6

AI summary

An electronic device and a display apparatus, the electronic device comprising a display apparatus and a camera module. The display apparatus comprises a pixel definition layer, an organic light emitter, a common electrode layer and a filling layer; the common electrode layer covers the organic light emitter and the pixel definition layer; a filling member of the filling layer is provided on the side of the common electrode layer facing away from the organic light emitter and provided opposite a pixel hole; the difference between the refractive indexes of the pixel definition layer and the filling member is smaller than the difference between the refractive indexes of the pixel definition layer and the vacuum; and the camera module acquires an image through the display apparatus.