Impedance Compensator for Display Power Line Voltage Drop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light emitting displays experience non-uniform brightness due to varying voltage drops across pixel power source lines of different lengths, leading to inconsistent current supply to pixels.
Innovation Solution
Incorporating an impedance compensator to equalize voltage drops between first and second power source lines, ensuring uniform power distribution to pixels by compensating for differences in line resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single power source line is used to supply power to all pixels, then the device complexity is reduced, but the brightness uniformity deteriorates due to varying voltage drops
Solution Approach 1:
The power source line is divided into multiple segments (first power source line and second power source line) that supply power to different regions of the pixel array. Each segment is independently configured to compensate for voltage drops in its respective region, thereby maintaining uniform brightness without excessive complexity
Solution Approach 2:
Different regions of the pixel array are provided with power source lines having different characteristics (impedances) tailored to their specific needs. The impedance compensator applies different compensation values to different regions based on their distance from the power source, ensuring local optimization of brightness uniformity
2Area of stationary object
If power source lines of different lengths are used to reach all pixels, then the coverage area is improved, but the brightness uniformity deteriorates due to non-uniform voltage drops
Solution Approach 1:
The impedance compensator changes the electrical parameters (impedance values) of the power source lines based on their length and position. By adjusting the impedance compensation value for each region, the system compensates for the non-uniform voltage drops caused by lines of different lengths, maintaining uniform brightness across the entire pixel area
3Illumination intensity
If impedance compensation is applied to all power source lines, then the brightness uniformity is improved, but the device complexity increases
Solution Approach 1:
The impedance compensator is designed to perform multiple functions: it compensates for voltage drops in both the first and second power source lines, and can also compensate for data line voltage drops. This multi-functionality justifies the added complexity by providing comprehensive compensation across the entire display system
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 maintains consistent brightness across all pixels by minimizing the ratio of maximum to minimum current supplied, thereby enhancing display uniformity and preventing non-uniformity caused by positional variations in power source line lengths.
Implementation Method 1
an impedance compensator connected to at least one of the first power source line and the second power source line to compensate for the difference in the voltage drop between the first power source line and the second power source line
Data Source
AI summary
A light emitting display includes a substrate, a pixel area, a first power source line to supply a first power signal to each pixel on a first side of the pixel area, a second power source line to supply the first power signal to each pixel on a second side of the pixel area, and an impedance compensator for compensating a difference in a voltage drop between the first power source line and the second power source line. A voltage drop caused by line resistance that depends on the length of the first and second power source line that supply the first power signal to a lower and upper side of a pixel area, respectively, is equalized, thereby minimizing the voltage drop of the first power signal supplied to all pixels, and minimizing non-uniformity of brightness due to the voltage drop differences at each pixel.