Pixel Driving Circuit Reset Signal Segmentation for Voltage Leakage
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Solution Overview
Problem
In OLED display technology, existing pixel driving circuits face challenges in maintaining voltage levels during low-frequency displays, leading to voltage leakage and compromised contrast and flickering due to shared reset signal lines.
Innovation Solution
The proposed pixel driving circuit includes independent first and second reset signal lines and a dual signal switch sub-circuit, generating initialization and voltage maintaining signals in different phases to prevent voltage leakage by maintaining distinct voltage levels across the reset transistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a shared reset signal line is used for both reset and voltage maintaining phases, then device complexity is reduced, but voltage leakage increases and contrast deteriorates
Solution Approach 1:
The patent divides the reset signal line into two independent lines: a first reset signal line for reset phase operations and a second reset signal line for voltage maintaining phase operations. This segmentation allows each line to serve its specific function without interference, preventing voltage leakage that occurs when a shared line is used, while the overall structure remains relatively simple.
2Use of energy by moving object
If voltage levels are not maintained during low-frequency display, then energy consumption is reduced, but voltage leakage occurs and flickering appears
Solution Approach 1:
The patent implements periodic voltage maintaining operations during low-frequency display periods. The second reset signal line is activated to maintain voltage levels at the gate electrode of the driving transistor during intervals when the display is not actively updating. This periodic maintenance prevents voltage leakage and eliminates flickering without requiring continuous high energy consumption.
3Reliability
If initialization voltage is continuously applied, then voltage stability is maintained, but unnecessary voltage application causes leakage during voltage maintaining phase
Solution Approach 1:
The patent dynamically switches between different voltage application modes based on the operational phase. During the reset phase, the first reset signal line applies initialization voltage to set up the driving transistor. During the voltage maintaining phase, the second reset signal line applies a different voltage level to maintain stability without causing leakage. This dynamic adaptation of voltage levels according to phase requirements eliminates unnecessary voltage application and its associated leakage problems.
Data Source
AI summary
A pixel driving circuit is provided. The pixel driving circuit includes a data write sub-circuit connected to a data line and connected to a second capacitor electrode, the data write sub-circuit configured to write a voltage of a data voltage signal and a threshold voltage of a driving transistor into the second capacitor electrode in a data write phase; a light emitting control sub-circuit connected to the driving transistor, the light emitting control sub-circuit configured to control a voltage supply signal of a voltage supply line to be written into the driving transistor to generate a driving signal in a light emitting phase; and a first reset transistor having a gate electrode connected to a reset control signal line, a source electrode connected to a first reset signal line, and a drain electrode connected to the gate electrode of the driving transistor and the second capacitor electrode.