OLED Pixel Circuit Layout for Slim Bezels and Luminance Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The complexity of driving circuits in active-matrix organic light emitting diode displays leads to increased bezel areas, making it difficult to achieve a slim bezel design, and non-uniform electrical characteristics of driving transistors cause luminance deviations between pixels.
Innovation Solution
A simplified pixel circuit design incorporating a driving transistor, first, second, and third transistors connected to a data line, power line, and a storage capacitor, respectively, along with a fourth transistor for initialization voltage supply, reduces circuit complexity and allows for a slim bezel by optimizing gate and data line configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a complex driving circuit is used to control the pixel circuit, then the luminance uniformity can be improved, but the bezel area increases
Solution Approach 1:
The patent extracts the compensation function from a complex external driving circuit and integrates it into a simplified pixel circuit structure. By incorporating compensation transistors and capacitors directly within the pixel, the circuit achieves luminance uniformity compensation without requiring additional external circuit components, thus reducing the bezel area while maintaining manufacturing precision.
Solution Approach 2:
The patent merges the driving function and compensation function into a single integrated pixel circuit. The driving transistor, compensation transistors, and storage capacitors are combined in one circuit block, allowing the pixel to self-compensate for threshold voltage variations and mobility differences without external intervention, thereby reducing the overall circuit complexity and bezel area.
2Area of stationary object
If the driving circuit is simplified to reduce bezel area, then the manufacturing precision may deteriorate
Solution Approach 1:
The pixel circuit is designed to be self-compensating through internal transistors and capacitors that automatically adjust for process variations and electrical characteristic non-uniformities. The compensation transistors sense threshold voltage differences and the storage capacitors maintain compensation charges, enabling the circuit to self-correct luminance deviations without external control, thus maintaining manufacturing precision with a simplified circuit.
3Manufacturing precision
If more transistors and capacitors are added to the pixel circuit for compensation, then the luminance non-uniformity is reduced, but the device complexity increases
Solution Approach 1:
The compensation transistors and capacitors in the pixel circuit serve multiple functions: they compensate for threshold voltage variations, store compensation charges, and regulate the driving current. This multi-functionality allows the circuit to achieve luminance uniformity without requiring separate dedicated components for each compensation function, thereby reducing overall device complexity while maintaining manufacturing precision.
Data Source
AI summary
A pixel circuit and a display device including the same are disclosed. The pixel circuit includes: a driving transistor which includes a first electrode connected to a first node, a gate electrode connected to a second node, and a second electrode connected to a third node, and supplies a driving current to a light emitting device; a first transistor that is electrically connected between the first node and the second node; a second transistor that is electrically connected between the first node and a data voltage; a third transistor that is electrically connected between the first node and a power supply line that supplies a high potential voltage; and a storage capacitor that includes a first electrode connected to the high potential voltage and a second electrode connected to the second node.