P-Type Scan Driver Stage for OLED Noise Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In organic light emitting diode (OLED) display devices, achieving stable drive reliability for scan signals is challenging due to the instability of N-type transistors used in stages, leading to potential data signal misalignment and luminance issues.
Innovation Solution
A stage and scan driver design utilizing P-type transistors with specific signal processing and stabilization circuits to control and stabilize scan signals, ensuring reliable voltage management and minimizing noise during signal supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If N-type transistors are used in stages to minimize leakage current, then leakage current is reduced, but drive reliability deteriorates due to instability of the scan signal
Solution Approach 1:
The patent inverts the conventional approach by using P-type transistors instead of N-type transistors in the stage circuitry. This inversion allows the scan signal to be maintained at a high level (ELVDD) rather than low level, providing stable drive reliability while still minimizing leakage current through the inherent characteristics of P-type transistors in this configuration
Solution Approach 2:
The patent changes the voltage level parameter of the scan signal from low level to high level (ELVDD) by using P-type transistors. This parameter change transforms the scan signal characteristics to achieve both low leakage current and high drive reliability simultaneously, resolving the technical contradiction
2Reliability
If P-type transistors are used to generate stable high-level scan signals, then drive reliability is improved, but device complexity increases due to additional stabilization circuits
Solution Approach 1:
The patent merges the stabilization function into the existing stage circuitry by integrating stabilization circuits that work cooperatively with the P-type transistor-based scan signal generation. The first and second stabilization circuits are combined with the stage components to maintain voltages of nodes N1-N6, achieving reliable scan signal generation without proportionally increasing overall device complexity
3Stability of the object's composition
If multiple stabilization circuits are added to control voltages of nodes N1-N6, then scan signal stability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The stabilization circuits are designed to automatically maintain the voltages of nodes N1-N6 through self-regulating mechanisms. The circuits monitor and adjust their own operation to keep scan signal voltages stable, reducing the need for external precision control and thereby lowering manufacturing precision requirements while maintaining scan signal stability
Data Source
AI summary
A stage and a scan driver including the same for supplying a scan signal using a stage formed of P-type transistors to prevent output of an unwanted noise in a period where the scan signal is not supplied.