OLED Aperture Ratio via Current Scaling
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Solution Overview
Problem
Conventional organic light emitting display devices face challenges in maintaining a high aperture ratio and lifespan due to voltage drops and heat generation in current supplying lines, which are exacerbated by the need for wider lines to handle high electrical currents, leading to reduced brightness and increased manufacturing costs.
Innovation Solution
The implementation of a system that restricts the electrical current supplied to the display panel based on a reference current value, using a scale parameter generator to adjust the current levels, thereby reducing the width of current supplying lines and optimizing the aperture ratio and lifespan, while also minimizing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the width of current supplying line is increased to reduce voltage drop and heat generation, then the reliability and temperature stability are improved, but the aperture ratio is reduced
Solution Approach 1:
The patent changes the electrical parameter (current level) from high to low by introducing a scale parameter generator that converts high-current pixel data to low-current output. This parameter change allows the current supplying line width to be reduced while maintaining reliability, as the lower current produces less heat and voltage drop, enabling thinner lines without sacrificing performance
Solution Approach 2:
The patent applies preliminary anti-action by proactively reducing the electrical current before it reaches the current supplying lines. The scale parameter generator pre-processes the pixel data to limit current to a predetermined level, preventing excessive heat generation and voltage drop before they occur, which allows for reduced line width while maintaining system reliability
2Illumination intensity
If high electrical current is applied to achieve high brightness, then the illumination intensity is improved, but the lifespan is reduced
Solution Approach 1:
The patent changes the current parameter from high to low by using a scale parameter generator that multiplies pixel data by a scale factor to produce output signals at a predetermined current level. This parameter transformation enables the display to operate at lower currents that extend organic material lifespan while maintaining perceptible brightness through optimized scaling algorithms
3Area of stationary object
If the width of current supplying line is reduced to increase aperture ratio, then the area of display is improved, but the voltage drop and heat generation are exacerbated
Solution Approach 1:
The patent fundamentally changes the current parameter from high to low using the scale parameter generator, which transforms high-current pixel data into low-current output signals. This parameter change reduces the energy loss in current supplying lines, allowing for reduced line width and increased aperture ratio without suffering from excessive voltage drop or heat generation
4Area of stationary object
If the electrical current is restricted to reduce current supplying line width, then the aperture ratio is improved, but the brightness may be reduced
Solution Approach 1:
The patent applies parameter changes by introducing a scale parameter that transforms pixel data values to correspond to reduced current levels. The scale parameter generator multiplies input pixel data by this scale factor, creating a linear relationship between input and output that maintains proportional brightness representation while operating at lower current levels that enable reduced line width and increased aperture ratio
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 approach effectively increases the aperture ratio and extends the lifespan of the display device by reducing the line width of current supplying lines, lowering power consumption, and simplifying manufacturing processes, while maintaining adequate brightness.
Implementation Method 1
An organic light emitting display device is a type of a flat panel display device which uses an electroluminescent phenomenon of an organic material
Data Source
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AI summary
An organic light emitting display which includes a display panel having a pixel cell formed in a region defined by gate lines and data lines perpendicularly crossing each other, a power supply which supplies current to the display panel, a scan driver which supplies a scan signal to a gate line, a data driver which supplies a data voltage to a data line, a timing controller which supplies a control signal to the scan driver and the data driver and an converted pixel data signal to the data driver, a gradation converter which converts a gradation of a pixel data signal inputted and supplies the converted pixel data signal to the timing controller, and a scale parameter generator which generates a scale parameter through the converted pixel data signal and supplies the scale parameter to the gradation converter, when the next pixel data signal is inputted to the gradation converter.