Stacked Micro LED Sub-Units for Brightness and Color Purity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Micro LED displays face challenges in handling small-sized light emitting diodes, particularly in mounting and replacing defective LEDs, due to their tiny size and the increased area occupied by sub-pixels, leading to reduced brightness and complex manufacturing processes.
Innovation Solution
The development of a display apparatus with a stacked structure of LED sub-units, where each sub-unit includes a semiconductor layer connected via a single via, allowing for independent driving and reduced light interference, and the use of color filters to prevent secondary light generation, enabling increased light emitting area without expanding pixel size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If micro LEDs are arranged on a two-dimensional plane, then the display can implement various colors through sub-pixels, but the area occupied by each pixel increases and the micro LEDs become difficult to handle and mount
Solution Approach 1:
The patent transitions from a two-dimensional arrangement of micro LEDs to a three-dimensional stacked structure. Multiple LED stacks are arranged vertically, with each stack containing multiple sub-units that emit different colors. This vertical stacking allows the display to maintain color versatility while reducing the horizontal footprint and simplifying the handling process, as entire stacks can be mounted as single units rather than individual micro LEDs.
2Quantity of substance
If the area of each sub-pixel is reduced to fit within a limited pixel area, then more sub-pixels can be arranged, but the brightness deteriorates due to reduced luminous area
Solution Approach 1:
By stacking multiple LED sub-units vertically within each pixel, the patent increases the total luminous area without expanding the horizontal pixel footprint. Each stack contains multiple sub-units that can be independently controlled, allowing the display to maintain or increase brightness while fitting more functional elements within the same pixel area.
Solution Approach 2:
Each LED stack is divided into multiple sub-units with different color emission characteristics. These sub-units can be independently controlled to produce various colors through color mixing. This segmentation allows the pixel to maintain high brightness by utilizing the cumulative luminous area of all sub-units while achieving color versatility through selective activation.
3Area of moving object
If multiple LED stacks are stacked vertically, then the light emitting area increases, but light interference between stacks may occur
Solution Approach 1:
The patent applies color filters to specific regions between LED stacks to selectively transmit desired wavelengths while blocking unwanted light. Each color filter is positioned locally to manage the light output from adjacent stacks, allowing the structure to maintain high light emitting area while preventing color contamination and light interference through localized optical control.
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 enhances the reliability and manufacturing efficiency of micro LED displays by simplifying the mounting process, reducing light interference, and maintaining brightness, while allowing for active matrix driving and independent control of each LED sub-unit.
Implementation Method 1
a first LED sub-unit disposed on the TFT substrate, a second LED sub-unit disposed on the first LED sub-unit, a third LED sub-unit disposed on the second LED sub-unit
Data Source
AI summary
A display apparatus including a thin film transistor (TFT) substrate; a first LED sub-unit, a second LED sub-unit, and a third LED sub-unit; first, second, third, and fourth electrode pads disposed between the TFT substrate and the first LED sub-unit; and connectors connecting the first, second, and third LED sub-units to a respective one of the electrode pads, in which the first, second, and third sub-units are configured to be independently driven; light generated from the first LED sub-unit is emitted to the outside of the display apparatus by passing through the second and third LED sub-units; light generated from the second LED sub-unit is emitted to the outside of the display apparatus by passing through the third LED sub-unit; and at least one of the connectors includes a first portion electrically connecting a first surface of the first LED sub-unit to the second electrode pad.