OLED Pixel Circuit Layout for Fine Luminance Current Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increase in definition of display apparatuses with light-emitting devices containing organic EL material reduces the area of the light-emitting surface, leading to a decrease in the amount of current capable of flowing through the device, necessitating fine control of current for luminance adjustment.
Innovation Solution
The display apparatus incorporates specific configurations of transistors and capacitors to control the current flowing through light-emitting devices, including various switch combinations and capacitor connections to achieve precise current management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the definition of light-emitting devices is increased, then the display resolution is improved, but the area of the light-emitting surface becomes small
Solution Approach 1:
The pixel circuit is divided into multiple functional blocks including first and second switching circuits, driving transistor, and capacitor components. This segmentation allows each component to be optimized independently for high-definition display while managing the limited light-emitting surface area through efficient spatial arrangement of circuit elements.
2Manufacturing precision
If the area of the light-emitting surface is reduced, then the display definition increases, but the amount of current capable of flowing through the device decreases
Solution Approach 1:
The switching circuits are designed to dynamically control current flow through the light-emitting device. The first and second switching circuits can adjust current levels in real-time, enabling fine control of luminance despite the reduced current-carrying capacity of the smaller light-emitting surface area.
Solution Approach 2:
The patent employs parameter changes in the switching circuits to modulate current flow characteristics. By adjusting switching timing, duty cycles, and voltage levels, the system achieves precise current control suitable for high-definition displays with limited current capacity.
3Manufacturing precision
If the current amount is reduced, then the display definition improves, but fine control of current becomes necessary for luminance adjustment
Solution Approach 1:
Multiple switching functions are merged into integrated switching circuits that perform both current regulation and pixel selection. The first and second switching circuits work in combination with the driving transistor to provide fine current control while reducing the overall complexity compared to using separate control circuits for each function.
Solution Approach 2:
The capacitor components serve as intermediaries between the switching circuits and the light-emitting device. These capacitors store and regulate current, providing fine control of luminance while simplifying the direct control requirements between switching elements and the light-emitting device.
Data Source
AI summary
A display apparatus with high display quality is provided. One embodiment of the present invention is a display apparatus including a pixel and a circuit. The pixel includes a light-emitting device, a driving transistor, first to fourth switches, and a first capacitor. The circuit includes a fifth switch, a sixth switch, and a second capacitor. A gate of the driving transistor is electrically connected to a first terminal of the first switch, a first terminal of the second switch, and a first terminal of the first capacitor. One of a source and a drain of the driving transistor is electrically connected to a second terminal of the first capacitor, a first terminal of the fourth switch, and an anode of the light-emitting device. The other of the source and the drain of the driving transistor is electrically connected to a second terminal of the second switch and a first terminal of the third switch. A second terminal of the first switch is electrically connected to a first terminal of the second capacitor. A first terminal of the fifth switch is electrically connected to a first terminal of the sixth switch and a second terminal of the second capacitor.