Organic Light Emitting Display Power Line Segmentation
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Solution Overview
Problem
In organic light emitting display devices, variations in power supplied to each pixel due to differing line resistances cause unequal luminance across the display, leading to inconsistent image quality.
Innovation Solution
The implementation of an organic light emitting display device with a substrate featuring a first power line and an auxiliary power line, along with a power comparator and DC-DC converters for the power supplies, which compare and adjust voltages to ensure equalization of power distribution to each pixel, using pixel power lines that extend vertically and horizontally to connect pixels uniformly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single power line is used to supply power to all pixels, then the device structure is simple, but the line resistance varies depending on pixel position causing unequal luminance
Solution Approach 1:
The power supply system is segmented into a first power line and a second power line, with pixels divided into a first pixel group and a second pixel group. Each group is supplied by its dedicated power line, reducing the effective length and resistance of each power line segment, thereby minimizing voltage drop variations and achieving uniform luminance across the display.
Solution Approach 2:
The power lines are arranged in different spatial dimensions - the first power line is positioned in a first non-display area while the second power line is positioned in a second non-display area. This spatial separation allows both power lines to serve multiple pixels simultaneously with reduced resistance, solving the luminance uniformity problem without increasing overall device complexity.
2Reliability
If pixel power lines are extended to reach all pixels, then all pixels can be powered, but the line resistance increases causing greater voltage drop and power variation
Solution Approach 1:
The pixel population is segmented into two groups, each served by a separate power line. This segmentation reduces the maximum length any single power line must traverse, thereby reducing the total resistance and voltage drop for each power line while ensuring all pixels receive adequate power.
3Area of stationary object
If the first power line and second power line are positioned in the same non-display area, then the device structure is compact, but the power distribution to pixels remains unequal due to position-dependent resistance
Solution Approach 1:
The first power line is positioned in a first non-display area while the second power line is positioned in a second non-display area, utilizing different spatial zones. This dimensional separation allows both power lines to reach their respective pixel groups with minimized resistance, achieving equal power distribution while maintaining compact device structure.
Data Source
AI summary
An organic light emitting display device includes a substrate including a display area on which a plurality of pixels are formed and a non-display area surrounding the display area; a first power line positioned on a lower non-display area; an auxiliary power line positioned on an upper non-display area; a first power supply supplying a first voltage to the first power line; and an auxiliary power supply supplying an auxiliary voltage to the auxiliary power line. Accordingly, it is possible to provide an organic light emitting display device capable of equalizing luminance by minimizing a variation in power supplied to each pixel.