Quantum Dot Display With Light-Blocking Matrix And Collimated Light
Solution Overview
Problem
Backlight units in electronic devices often fail to efficiently illuminate display pixels and achieve desired color performance, especially in varying ambient lighting conditions.
Innovation Solution
The use of quantum dot elements, a light source with an edge-lit light guide or array of individually adjustable light-emitting devices, and polarizer layers to modulate light intensity, combined with a light-blocking matrix and color filter elements, along with low-index substrate layers to enhance light recycling and collimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a traditional backlight unit is used, then the display can be illuminated, but the light does not efficiently illuminate display pixels and color performance is poor
Solution Approach 1:
The patent changes the spectral parameters of the light source by using quantum dot elements with specific size ranges (2-10 nm) that emit at precise wavelengths (450-480 nm for blue, 560-580 nm for green, 610-650 nm for red). This parameter optimization enables efficient pixel illumination while maintaining energy efficiency.
Solution Approach 2:
The patent employs composite material structures including quantum dot elements embedded in matrix materials, multiple functional layers (color filters, polarizers, collimating layers), and semiconductor dies with phosphor materials. These composite structures work together to achieve efficient light conversion and pixel illumination.
2Manufacturing precision
If a traditional backlight unit is used, then the display can function, but desired color performance is not achieved
Solution Approach 1:
The patent applies local quality by positioning specific quantum dot elements (blue, green, red) at specific locations corresponding to different pixel types. Each pixel region receives targeted light from quantum dots of the appropriate color, enabling precise color control and accurate color representation.
Solution Approach 2:
The patent segments the backlight unit into multiple independent quantum dot elements and light-emitting devices that can be individually controlled. This segmentation allows precise color tuning for each pixel type and enables independent optimization of color performance without affecting the entire display.
3Illumination intensity
If light-emitting diodes are covered with high-index-of-refraction material to form waveguide structures, then light distribution is improved, but waveguide losses occur
Solution Approach 1:
The patent introduces low-index-of-refraction intermediary layers (with refractive index 1.3-1.6) between the high-index semiconductor dies and the quantum dot elements. These intermediary layers reduce total internal reflection at interfaces, enabling more efficient light extraction from the waveguide structure and reducing waveguide losses.
4Productivity
If pump light is used to excite quantum dot elements, then color emission is achieved, but light recycling efficiency varies with angle
Solution Approach 1:
The patent implements dynamic light management by using collimating layers with angularly dependent transmission characteristics. These layers dynamically redirect off-axis light rays back toward the quantum dot elements for recycling, while allowing on-axis light to pass through to the pixels, optimizing light recycling efficiency across varying angles.
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 display efficiency by ensuring uniform illumination and accurate color representation across different lighting conditions, reducing waveguide losses and preventing crosstalk between pixels.
Implementation Method 1
quantum dot elements, a light source with an edge-lit light guide or array of individually adjustable light-emitting devices, and polarizer layers to modulate light intensity
Implementation Method 2
The waveguide structures may have light-redirecting structures such as gratings for redistributing light from the light-emitting diodes outwards through the pixel array
Implementation Method 3
polarizer layers to modulate light intensity, combined with a light-blocking matrix and color filter elements, along with low-index substrate layers to enhance light recycling and collimation
Implementation Method 4
A low-index portion of the second substrate layer may be formed from recesses in a surface of the second substrate layer that faces the first and second layers
Data Source
AI summary
A display may have display layers that form an array of pixels. The display layers may include a first layer that includes a light-blocking matrix and a second layer that overlaps the first layer. The first layer may include quantum dot elements formed in openings in the light-blocking matrix. The light-blocking matrix may be formed from a reflective material such as metal. The second layer may include color filter elements that overlap corresponding quantum dot elements in the first layer. Substrate layers may be used to support the first and second layers and to support thin-film transistor circuitry that is used in controlling light transmission through the array of pixels. The display layers may include a liquid crystal layer, polarizer layers, filter layers for reflecting red and green light and/or other light to enhance light recycling, and layers with angularly dependent transmission characteristics.