RGB Light-Emitting Stack Structure for Sub-Pixel and Color Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED display apparatuses face challenges in increasing sub-pixel area within a restricted pixel area, reducing mounting process time, and easily controlling the RGB mixing ratio due to the limitations of current LED chip arrangements and luminance intensity ratios.
Innovation Solution
A light emitting device comprising a first, second, and third light emitting stack, each emitting red, blue, and green light respectively, with transparent conductive oxide layers and varying thicknesses of lower contact electrodes to control luminance intensity and RGB mixing ratios, allowing for increased sub-pixel area and reduced mounting time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If one LED chip is arranged in each sub-pixel, then the display can show various colors, but the number of LED chips increases substantially, requiring excessive mounting time
Solution Approach 1:
The patent combines multiple LED chips (red, green, and blue LEDs) into a single integrated LED chip structure. This single chip contains multiple light-emitting regions that can emit different colors, thereby reducing the total number of chips from three per pixel to one per pixel, and significantly decreasing mounting time while maintaining full-color display capability.
Solution Approach 2:
The patent transitions from a planar arrangement of separate LED chips to a vertical stacked structure where multiple light-emitting layers are arranged in different dimensions within a single chip. This three-dimensional integration allows multiple colors to be emitted from a single chip location, reducing the number of components without compromising color display versatility.
2Productivity
If the area of each sub-pixel is reduced to arrange sub-pixels in a restricted area, then more sub-pixels can be arranged, but the luminous area of sub-pixels is reduced, deteriorating pixel brightness
Solution Approach 1:
The patent employs a vertical stacked structure where multiple light-emitting layers (red, green, blue LEDs) are arranged in the vertical dimension rather than spreading them out in the horizontal plane. This allows the sub-pixel to maintain a small footprint for high pixel density while the cumulative luminous area of all LED layers contributes to sufficient brightness output.
Solution Approach 2:
The patent nests multiple light-emitting regions within a single sub-pixel structure, with each color channel (red, green, blue) containing its own LED chips arranged in a compact configuration. This nested arrangement maximizes the use of available space, allowing multiple light sources to coexist within a restricted area without compromising individual luminous area.
3Illumination intensity
If LED chips with high blue luminance intensity are used, then the LED performance is improved, but it becomes difficult to match the RGB mixing ratio of 3:6:1 for standard white light
Solution Approach 1:
The patent applies different quantities or configurations of red, green, and blue LED chips within each sub-pixel to compensate for the inherently high blue luminance intensity. By adjusting the local composition (e.g., using fewer blue chips or adding optical filters), the overall RGB mixing ratio can be tuned to achieve the desired 3:6:1 proportion for standard white light, while still utilizing high-performance blue LEDs.
Solution Approach 2:
The patent adjusts various parameters such as the number of LED chips per color channel, the active area of each chip, the drive current, or the addition of optical filtering layers to modify the effective luminance output. These parameter changes allow the system to balance the RGB mixing ratio to 3:6:1 even when using blue LEDs with high intrinsic luminance intensity.
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 effectively increases sub-pixel area, reduces mounting process time, and facilitates easy control of the RGB mixing ratio, enhancing the display quality and manufacturing efficiency of LED display apparatuses.
Implementation Method 1
A light emitting device according to an exemplary embodiment includes a first light emitting stack, a second light emitting stack, and a third light emitting stack, each including a first conductivity type semiconductor layer and a second conductivity type semiconductor layer
Data Source
AI summary
A light emitting device including first, second, and third light emitting stacks each including first and second conductivity type semiconductor layers, a first lower contact electrode in ohmic contact with the first light emitting stack, and second and third lower contact electrodes respectively in ohmic contact with the second conductivity type semiconductor layers of the second and third light emitting stacks, in which the first lower contact electrode is disposed between the first and second light emitting stacks, the second and third lower contact electrodes are disposed between the second and third light emitting stacks, and the first, second, and third lower contact electrodes include transparent conductive oxide layers.