Organic Light Emitting Display Voltage Supply Line Segmentation
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Solution Overview
Problem
As organic light emitting display devices increase in size, the increased length of voltage supply lines leads to higher line resistance, resulting in a deviation in the potential difference between the anode and cathode, which decreases luminance uniformity.
Innovation Solution
A compensation method is introduced where the anode voltage supply line and cathode voltage supply line are optimized with opposite input directions, and their line resistances are kept within a 10% difference, ensuring uniform potential difference across sub-pixels by gradually decreasing anode voltage and increasing cathode voltage along the line length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the display device size is increased, then the display area is enlarged, but the line resistance increases causing potential difference deviation
Solution Approach 1:
The voltage supply lines are divided into multiple segments (first voltage supply line and second voltage supply line) that extend in opposite directions from different sides of the substrate. This segmentation allows each line to serve a specific region, reducing the overall line length and resistance in each segment while covering the entire display area.
Solution Approach 2:
The first and second voltage supply lines are configured with asymmetric positioning - one extends from a first side along a first direction while the other extends from a second side along a second direction. This asymmetric arrangement optimizes the voltage distribution across different regions of the enlarged display, compensating for the increased line resistance by creating balanced voltage drops from opposite directions.
2Length of stationary object
If the voltage supply line length is increased, then the display device can be enlarged, but the line resistance increases
Solution Approach 1:
The voltage supply system is segmented into multiple independent lines extending from opposite sides. Each line serves a portion of the display area, effectively reducing the length of individual supply lines and minimizing the cumulative resistance loss while still supporting the overall enlarged display size.
Solution Approach 2:
Instead of extending voltage supply lines in a single direction across the entire display, the invention introduces a multi-directional approach with lines extending from opposite sides. This dimensional change in the supply architecture reduces the effective path length and resistance by utilizing both directions simultaneously.
3Area of stationary object
If the line resistance increases, then the display device can be larger, but the luminance uniformity decreases
Solution Approach 1:
The asymmetric configuration of voltage supply lines from opposite sides creates a balanced voltage distribution pattern across the display. By positioning lines at different locations and extending them in opposite directions, the design compensates for resistance-induced voltage drops, ensuring uniform potential difference and thus uniform luminance across the entire enlarged display area.
Solution Approach 2:
The multi-directional voltage supply architecture works to maintain equipotential conditions across the display by providing voltage paths from opposite directions. This helps equalize the potential difference across different regions, compensating for the voltage drops caused by increased line resistance in larger displays, thereby maintaining uniform luminance.
Data Source
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AI summary
Provided is an organic light emitting display device. The organic light emitting display device includes: a plurality of sub-pixels including an anode and a cathode; an anode line configured to supply an anode voltage to the anode; and a cathode line configured to supply a cathode voltage to the cathode, and in each of the plurality of sub-pixels, a direction of an anode voltage input of the anode line and a direction of a cathode voltage input of the cathode line are different from each other and face each other in order to reduce a deviation in a potential difference between the anode and the cathode. Thus, it is possible to improve uniformity in the potential difference between the anode and the cathode caused by a line resistance.