High-Pixel-Density LED Subpixels With Quantum Dot Pixel Repair
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Solution Overview
Problem
Conventional methods struggle to produce high-quality, high-pixel-density LED display devices with minimal defects and crosstalk, particularly at densities greater than 1000 pixels per inch, due to challenges in isolating and replacing defective subpixels without disrupting adjacent subpixels and control circuitry.
Innovation Solution
The method involves bonding a backplane substrate with CMOS circuitry to an LED substrate, forming quantum dot layers on subpixels, and using pixel isolation structures to prevent crosstalk, with a UV barrier layer to absorb ultraviolet light and enhance image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pixel density is increased above 600 ppi, then display resolution is improved, but pixel defects and crosstalk increase
Solution Approach 1:
The patent divides each pixel into multiple subpixels (e.g., red, green, blue subpixels) that can be independently controlled and repaired. This segmentation allows for targeted replacement of defective subpixels without affecting the entire pixel, thereby maintaining high display resolution while reducing the impact of pixel defects at densities above 600 ppi.
Solution Approach 2:
The patent modifies the structural parameters of pixels by reducing subpixel size and increasing subpixel density within each pixel. This parameter change enables achieving display resolutions above 600 ppi while implementing repair mechanisms for defective subpixels, thus improving display resolution without proportionally increasing pixel defect rates.
2Measurement precision
If pixel density is increased above 600 ppr, then display resolution is improved, but crosstalk between adjacent pixels increases
Solution Approach 1:
The patent introduces isolation structures (such as black matrix layers or dielectric layers) as intermediaries between adjacent subpixels. These intermediary structures prevent light from one subpixel from leaking into adjacent subpixels, thereby reducing crosstalk while maintaining the high subpixel density required for display resolutions above 600 ppi.
3Measurement precision
If pixel density is increased above 600 ppi, then display resolution is improved, but brightness is reduced
Solution Approach 1:
The patent transitions from controlling only the number of pixels to controlling the number and arrangement of subpixels within each pixel. By increasing subpixel density (a different dimensional approach) while maintaining or reducing individual subpixel size, the patent achieves display resolutions above 600 ppi while preserving brightness through optimized light emission from each subpixel.
4Reliability
If replacement quantum dot layers are formed to repair defective pixels, then pixel yield is improved, but manufacturing complexity increases
Solution Approach 1:
The patent incorporates spare subpixels during the initial manufacturing process, which can later be activated to replace defective subpixels. This preliminary action of creating redundant structures during manufacturing simplifies the repair process compared to creating entirely new pixels, thereby improving pixel yield while managing manufacturing complexity through planned redundancy.
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 approach results in high-pixel-density displays with fewer defects and reduced crosstalk, providing improved image quality for close-range viewing in devices like virtual reality headsets and augmented reality glasses.
Implementation Method 1
a quantum dot layer formed on at least one of the isolated subpixels in each of the LED pixels
Implementation Method 2
forming a UV barrier layer on the array of LED pixels
Data Source
AI summary
Methods of making high-pixel-density LED structures are described. The methods may include forming a backplane substrate and a LED substrate. The backplane substrate and the LED substrate may be bonded together, and the bonded substrates may include an array of LED pixels. Each of the LED pixels may include a group of isolated subpixels. A quantum dot layer may be formed on at least one of the isolated subpixels in each of the LED pixels. The methods may further include repairing at least one defective LED pixel by forming a replacement quantum dot layer on a quantum-dot-layer-free subpixel in the defective LED pixel. The methods may also include forming a UV barrier layer on the array of LED pixels after the repairing of the at least one defective LED pixel.