OLED Pixel Circuit With N-Channel TFTs for Gate Potential Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic EL display devices with p-channel transistors experience high driving power consumption and flicker issues due to large source-drain leakage and changes in gate potential during light emission.
Innovation Solution
The display device incorporates a pixel circuit with n-channel transistors, including a correction transistor, a switching transistor, and an initialization transistor, coupled with a capacitive element to reduce leakage current and stabilize gate potential, thereby reducing driving power and flickering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If p-channel transistors are used in the pixel circuit, then the device can be manufactured with standard processes, but the source-drain leakage current is large causing gate potential changes and flicker
Solution Approach 1:
The patent changes the transistor type parameter from p-channel to n-channel to fundamentally alter the electrical characteristics. This parameter change reduces source-drain leakage current by approximately one order of magnitude compared to p-channel transistors, thereby stabilizing the gate potential during light emission and eliminating flicker while maintaining compatibility with standard manufacturing processes
2Device complexity
If p-channel transistors are used in the pixel circuit, then the device structure is simplified, but the driving power consumption increases due to large leakage current
Solution Approach 1:
The patent changes the transistor type parameter from p-channel to n-channel, which reduces the leakage current by approximately one order of magnitude. This parameter change directly reduces the driving power consumption while maintaining the same pixel circuit structure and manufacturing process complexity
3Adaptability or versatility
If p-channel transistors are used in the pixel circuit, then the device can operate with standard voltage levels, but the amplitude of driving lines becomes large increasing power consumption
Solution Approach 1:
The patent changes the transistor type parameter from p-channel to n-channel, which reduces the required driving line amplitude. This parameter change reduces the driving power consumption while maintaining compatibility with standard voltage levels through appropriate voltage level design
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 configuration minimizes leakage current, stabilizes gate potential, and enhances image quality by reducing flickers and uneven luminance, achieving low power consumption and improved image clarity.
Implementation Method 1
An organic electroluminescence (EL) element utilizing a phenomenon of emitting light in response to applying of an electric field to an organic thin film
Data Source
AI summary
A display device includes a current-driven electro-optical element, a first supply, a second supply, a driving transistor, a correction transistor, an anode switching transistor, an initialization transistor, and a capacitive element. A current is supplied from the first supply. The second supply is lower in potential than the first supply. The driving transistor is configured to drive the electro-optical element in accordance with a written image signal. The correction transistor is coupled between a gate of the driving transistor and a second terminal of the driving transistor. The anode switching transistor is coupled between the second terminal of the driving transistor and an anode of the electro-optical element. The initialization transistor is coupled between the anode of the electro-optical element and the second supply. The capacitive element is coupled to the gate of the driving transistor. The correction, anode switching, and initialization transistors are n-channel transistors.