Quantum Dot Liquid Lens for Dynamic Color Gamut Control

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Solution Overview

Problem

Traditional display screen backlights suffer from uneven illumination, inflexibility in manufacturing, and limited color gamut due to the use of total internal reflection lenses and LEDs.

Innovation Solution

A lens comprising a transparent liquid with quantum dots that can alter its optical properties through electrowetting, allowing for dynamic wavelength down-conversion and adjustable color gamut, combined with a blue LED to produce white light with a high color gamut, and used in light-emitting electronic devices and backlights for display screens.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If traditional total internal reflection lenses and LEDs are used in backlights, then the manufacturing process is simple and reliable, but the illumination is uneven and the color gamut is limited

Engineering Contradiction:
Improveillumination uniformityVSAvoidoptics design flexibility
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent employs a liquid crystal lens that can dynamically change its optical properties (focal length, shape) in response to electrical signals, allowing the backlight to adapt and provide uniform illumination across the display screen, resolving the contradiction between illumination uniformity and optical design flexibility

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The liquid crystal lens changes its refractive index and physical shape parameters when voltage is applied, enabling dynamic control of light distribution to achieve even illumination while maintaining manufacturing simplicity

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If traditional fixed optics are used, then the manufacturing process is inflexible, but the device structure is simple

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidoptics structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The liquid crystal lens provides dynamic adaptability by allowing optical parameters to be adjusted after manufacturing, enabling the same device to serve multiple optical design requirements without changing the physical structure, thus achieving manufacturing flexibility without increasing structural complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The liquid crystal lens can perform multiple optical functions (focusing, collimating, beam shaping) by changing its operational parameters, making a single component versatile enough to replace multiple fixed optical elements

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

3Illumination intensity

If conventional LEDs with fixed spectral output are used, then the device is simple to manufacture, but the color gamut is limited

Engineering Contradiction:
Improvecolor gamutVSAvoidmanufacturing process complexity
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The liquid crystal lens manipulates the spectral distribution of light by changing its optical parameters, enabling enhancement of color gamut without requiring complex multi-LED configurations or phosphor conversion systems, thus improving color performance while keeping manufacturing simple

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

The solution provides improved, even illumination and a high color gamut for display screens, with the ability to dynamically adjust optical properties and manufacturing flexibility, significantly enhancing display quality and adaptability.

Implementation Method 1

the quantum dots transmit visible light of a longer wavelength than they receive

Methodology Applied
Scientific EffectWavelength down-conversion: Photoluminescence

Implementation Method 2

a surface profile of the transparent liquid can be changed in shape by electrowetting

Methodology Applied
Scientific EffectElectrowetting: Electrowetting

Data Source

PatentEP3418252B1Quantum dot liquid lens, devices comprising the same, method of manufacturing a quantum dot liquid lens, and method of operating a light emitting electronic device
Publication Date: 2022.11.16 VESTEL ELEKTRONIK SANAYI & TICARET ANONIM SIRKETI
  • EP3418252B1 patent drawingFigure 1A~1C
  • EP3418252B1 patent drawingFigure 2A~2B
  • EP3418252B1 patent drawingFigure 3A~3B

AI summary

The present invention provides a lens (5) at least comprising a transparent liquid with quantum dots (6) suspended therein, wherein the quantum dots transmit visible light of a longer wavelength than they receive. A surface profile of the transparent liquid may be changed in shape using the principle of electrowetting by electrically connecting electrodes (7) to the lens, so that one or more optical properties of the lens may be dynamically altered during the transmission of light thereby. The quantum dots (6) suspended in the transparent liquid can be used to down-convert the wavelength of light transmitted through the lens, and any of the shape, size, composition and concentration of the quantum dots may be varied to modify the optical properties of the lens, and in particular to modify the colour gamut of light transmitted by the lens. Thus, for example, the liquid lens (5) can be combined with a blue LED (2) in a light emitting electronic device, and the quantum dots (6) can be chosen to have a size distribution comprising two peaks configured to transmit light at green and red wavelengths. The blue light (3) emitted by the LED (2) can therefore be down-converted by the quantum dots (6) within the lens to provide green and red light, which mix with the blue light (3) from the LED to provide white light (4) with a high colour gamut. The present invention also provides a method of manufacturing such a lens, a method of operating a light emitting electronic device comprising such a lens, as well as a backlight for a display screen comprising a plurality of such light emitting electronic devices, and a luminaire also comprising a plurality of such light emitting electronic devices. Both the backlight for a display screen and the luminaire may therefore have their optical properties dynamically altered during emission of light thereby.