Display Panel Electrochromic Layer for Under-Display Camera Switching

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Solution Overview

Problem

The integration of both visible light and time-of-flight cameras under a display panel increases the optical components, adversely affecting the display performance.

Innovation Solution

A display panel design incorporating an electrochromic layer with adjustable light absorption properties, controlled by a processor, allows a single camera to switch between facial recognition and photography modes by altering its light absorption characteristics, reducing the need for multiple cameras and minimizing display interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If both visible light camera and ToF camera are disposed as under-display cameras, then facial recognition and photography functions are implemented, but more optical components adversely impact display performance

Engineering Contradiction:
Improvedual-functionality of cameraVSAvoiddisplay performance degradation
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

A single camera module is designed to perform both visible light photography and infrared facial recognition functions by incorporating both visible light and infrared filters, eliminating the need for separate camera modules and reducing optical component complexity

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

Solution Approach 2:

An electrochromic layer is introduced that can dynamically adjust its light absorption characteristics based on operational mode, switching between transparent and absorbing states to optimize performance for different camera functions while minimizing display interference

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If electrochromic layer is disposed in under-display photographing area, then light absorption can be adjusted for different camera modes, but the electrochromic layer may interfere with display light emission

Engineering Contradiction:
Improveadjustable light absorptionVSAvoiddisplay brightness
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The electrochromic layer transitions between different optical states (transparent and absorbing) based on applied voltage, allowing dynamic control of light transmission to match operational requirements without permanent display obstruction

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The optical properties of the electrochromic layer are changed by adjusting voltage parameters, enabling precise control over light absorption characteristics to balance camera functionality with display performance

Inventive Principle:
Principle #35Parameter changes

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 solution enables efficient dual-functionality without increasing optical components, improving display quality by reducing reflections and diffraction issues, while maintaining optimal performance in both facial recognition and photography scenarios.

Implementation Method 1

an electrochromic layer is disposed on a light-emitting side of the display layer... the electrochromic layer has a first light absorption feature under action of a first voltage difference, and has a second light absorption feature under action of a second voltage difference

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Data Source

PatentEP4280845B1Display panel and electronic device
Publication Date: 2025.07.30 HONOR DEVICE CO LTD
  • EP4280845B1 patent drawingFigure 1
  • EP4280845B1 patent drawingFigure 2~3
  • EP4280845B1 patent drawingFigure 4~5

AI summary

Embodiments of this application provide a display panel and an electronic device, and relate to the field of display technologies, to reduce adverse impact of an under-display optical component on display. For the display panel, in an under-display photographing area, an electrochromic layer is disposed on a light-emitting side of a display layer, and the electrochromic layer does not overlap a pixel area in a direction perpendicular to a plane on which the display panel is located; a first electrode layer is disposed on a side that is of the electrochromic layer and that is close to the display layer, and a second electrode layer is disposed on a side that is of the electrochromic layer and that is away from the display layer; and the electrochromic layer has a first light absorption feature under action of a first voltage difference, and has a second light absorption feature under action of a second voltage difference. The first light absorption feature is that the electrochromic layer has a first absorption rate for visible light and has a second absorption rate for infrared light, and the second light absorption feature is that the electrochromic layer has a third absorption rate for the visible light and a fourth absorption rate for the infrared light. The first absorption rate is greater than the third absorption rate, and the second absorption rate is less than the fourth absorption rate.