Pixel Driving Circuit for OLED Display Threshold Voltage Drift Compensation
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Solution Overview
Problem
The current OLED display technology faces issues due to threshold voltage drift in driving transistors affecting driving current and voltage fluctuations in touch driving signals, which degrade display quality.
Innovation Solution
A pixel driving circuit comprising a preset unit, compensation unit, energy storage unit, and driving signal output unit, which compensates the threshold voltage and stabilizes touch driving signals to maintain consistent display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional DTFT is used to drive OLED, then the circuit structure is simple, but the threshold voltage drift affects the driving current and degrades display quality
Solution Approach 1:
The pixel circuit is divided into multiple functional modules: a preset unit for initializing voltages, a compensation unit for threshold voltage compensation, an energy storage unit for maintaining stable voltages, and a driving signal output unit for controlled signal output. This segmentation allows each module to perform its specific function independently, resolving the threshold voltage drift issue without requiring a complete circuit redesign.
Solution Approach 2:
The preset unit applies predetermined voltages to the first and second nodes before the driving operation begins. The compensation unit also performs preliminary compensation by applying specific voltages to counteract the threshold voltage drift. These preliminary actions ensure that the driving transistor operates with stable and accurate voltages from the start, preventing display quality degradation.
2Length of stationary object
If the cathode is used as a touch electrode to reduce thickness, then the overall thickness is reduced, but the voltage fluctuation of touch driving signal affects display quality
Solution Approach 1:
The energy storage unit acts as an intermediary between the touch electrode and the driving transistor. It stores stable voltages at the first and second nodes, isolating the driving circuit from voltage fluctuations caused by touch driving signals. This intermediary structure allows the cathode to function as both touch electrode and stable voltage reference, maintaining display quality while enabling touch functionality.
Solution Approach 2:
The first node serves multiple functions: it stores voltage for the driving transistor operation, provides a stable reference voltage during touch operations, and maintains electrical potential during signal output. This multi-functionality allows the circuit to handle both display driving and touch sensing without compromising performance, resolving the contradiction between thinness and display quality.
Data Source
AI summary
The present disclosure provides in some embodiments a pixel driving circuit, a display panel, a method for driving the display panel, and a display device. The pixel driving circuit includes a preset unit, a driving unit, a compensation unit, an energy storage unit, and a driving signal output unit.