OLED Color Filter Asymmetry for Luminance Uniformity
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Solution Overview
Problem
Conventional white organic light emitting diode (OLED) displays face challenges in maintaining consistent luminance distribution across pixels, leading to color defects due to differences in lateral and front color characteristics.
Innovation Solution
The OLED display incorporates a substrate with a driving wire, color filters (blue, red, and green), and an OLED structure where the blue color filter is wider than the red or green, and includes a light path control layer with recess or convex portions to align light paths, ensuring similar luminance distribution at the side and front.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a white organic emission layer is used to improve luminance, then the luminance is improved, but the color characteristic cannot be optimized for each pixel and lateral color characteristics change
Solution Approach 1:
The patent applies local quality by making each color filter (red, green, blue) have different widths tailored to its specific pixel requirements. The blue color filter has a greater width than the red or green color filters, allowing each pixel type to optimize its color characteristics locally while using a common white emission layer
Solution Approach 2:
The patent introduces asymmetry by designing unequal widths for different color filters. Specifically, the blue color filter width is greater than the red or green color filter widths, creating an asymmetric structure that compensates for the different color characteristics of each pixel type and maintains consistent color perception across all pixels
2Device complexity
If color filters of equal width are used, then the structure is simple, but the luminance distribution at the side differs from the front causing color twist defects
Solution Approach 1:
The patent deliberately introduces asymmetry in the color filter widths to compensate for the different optical paths and color characteristics of red, green, and blue pixels. The blue color filter has a greater width than the red or green color filters, which balances the luminance distribution between front and side viewing angles across all pixel types
Solution Approach 2:
The patent changes the width parameter of the color filters differently for each color type. By adjusting the blue color filter width to be greater than the red or green color filter widths, the patent optimizes the luminance distribution and reduces color twist defects while maintaining a relatively simple overall structure
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 color twist defects by maintaining side luminance similar to front luminance, enhancing display quality by reducing color discrepancies and improving luminance distribution across pixels.
Implementation Method 1
Each OLED emits light by energy generated when excitons generated as electrons and holes are combined drop from an excited state to a ground state
Implementation Method 2
A red color filter, a green color filter, and a blue color filter are formed in a white organic emission layer emitting white light to realize the red, the green, and the blue
Data Source
AI summary
An organic light emitting diode display that maintains a luminance distribution characteristic of each pixel at the side substantially similar to a luminance distribution characteristic of each pixel at the front of the OLED display by improving a twist of a lateral color with respect to a front color. The organic light emitting diode display includes a substrate, a driving wire disposed on the substrate, a color filter disposed on the driving wire. The color filter includes a blue color filter, a red color filter, and a green color filter formed on the driving wire; and an organic light emitting diode disposed on the color filter, where a recess portion is defined at a lower surface of the blue color filter, and a convex portion is defined at a lower surface of the red color filter or the green color filter.