OLED Pixel Mux Driving to Minimize Transistor Hysteresis
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Solution Overview
Problem
In OLED display devices, hysteresis in the driving transistor occurs due to voltage differences during the initialization and sampling periods, leading to reduced response speed and inadequate light emission luminance.
Innovation Solution
A mux signal with a voltage close to the data signal is supplied to the gate electrode during the initialization period, and a method is employed to minimize hysteresis and improve the response speed of the driving transistor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a high level voltage signal is supplied to the gate electrode during the initialization period, then the gate electrode is initialized to a high voltage level, but a voltage difference between the initialization signal and data signal causes hysteresis in the driving transistor
Solution Approach 1:
The patent changes the voltage parameter of the initialization signal from a fixed high level to a variable level that is dynamically adjusted based on the data signal voltage. Specifically, the initialization signal voltage is set to be substantially equal to the data signal voltage, eliminating the voltage difference that causes hysteresis while still achieving proper gate electrode initialization
Solution Approach 2:
The patent applies preliminary action by initializing the gate electrode with a voltage that is pre-adjusted to match the upcoming data signal voltage before the data signal is actually applied. This preliminary voltage matching prevents hysteresis from occurring in the first place, rather than correcting it afterward
2Stability of the object's composition
If a high level voltage signal is supplied to the gate electrode during the initialization period, then the gate electrode reaches a high voltage level, but the response speed of the driving transistor is reduced due to hysteresis
Solution Approach 1:
The patent changes the voltage parameter of the initialization signal to match the data signal voltage, eliminating hysteresis and thereby improving the response speed of the driving transistor. The gate electrode transitions more quickly to the target voltage level because there is no hysteresis delay
Solution Approach 2:
By preliminarily setting the gate electrode voltage to match the data signal voltage before data input, the patent eliminates the need for the transistor to overcome hysteresis during the sampling period, thus improving response speed
3Stability of the object's composition
If a high level voltage signal is supplied to the gate electrode during the initialization period, then the gate electrode is initialized to a high voltage level, but the light emitting diode does not emit light of the predetermined luminance
Solution Approach 1:
The patent changes the initialization signal voltage parameter to be substantially equal to the data signal voltage, ensuring that the gate electrode is properly initialized without causing hysteresis. This results in the driving transistor correctly controlling the current to the light emitting diode, achieving the predetermined luminance
Solution Approach 2:
By preliminarily initializing the gate electrode with a voltage matching the data signal, the patent ensures that the driving transistor is ready to immediately control the light emitting diode at the correct luminance level without hysteresis-induced delays or inaccuracies
Data Source
AI summary
A display device includes a timing controlling circuit configured to generate image data, a data control signal and a gate control signal; a data driving circuit configured to generate a data signal using the image data and the data control signal and generate a mux signal using an offset signal, a high level voltage signal and the data signal; a gate driving circuit configured to generate gate signals, emission signals using the gate control signal; and a display panel including pixels that are configured to display an image using the data signal, the mux signal, the gate signals, and the emission signals, wherein the mux signal is one of the high level voltage signal and voltage that is a sum of the data signal and the offset signal, and the mux signal is supplied to a power line that is connected to a pixel included in the display panel.