Pixel Driving Circuit Threshold Voltage Compensation Using P-Type Transistors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display technologies face display unevenness due to inhomogeneity in threshold voltage of driving transistors, leading to complex processes and increased costs, especially when trying to simplify circuit control signals and manufacturing processes.
Innovation Solution
A pixel driving circuit with a driving transistor, scanning terminals, data input terminal, light emission control terminal, storage capacitor, reset unit, writing compensation unit, and light emission control unit, where the storage capacitor is connected to the driving transistor, and the reset and writing compensation units are controlled by separate scanning signals to reset and discharge the capacitor, eliminating the influence of threshold voltage on display evenness while using P-type transistors to simplify the circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If both P-type and N-type transistors are used in the pixel driving circuit to compensate for threshold voltage, then display evenness is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent uses only P-type transistors throughout the pixel driving circuit, eliminating the need for N-type transistors. This homogeneous transistor type approach simplifies the manufacturing process while maintaining the ability to compensate for threshold voltage variations through the capacitor discharge mechanism, thereby resolving the contradiction between display evenness and device complexity
Solution Approach 2:
The patent extracts and eliminates the N-type transistors from the circuit, keeping only P-type transistors. This extraction simplifies the circuit structure and manufacturing process while the remaining P-type transistors, combined with the capacitor discharge mechanism, still achieve effective threshold voltage compensation to maintain display evenness
2Ease of manufacture
If all transistors are changed to P-type transistors to simplify the manufacturing process, then ease of manufacture is improved, but device complexity increases due to additional control signals
Solution Approach 1:
The patent combines the reset function and threshold compensation function into a single capacitor discharge operation controlled by one scanning signal. The capacitor serves dual purposes: resetting the pixel and compensating for threshold voltage, eliminating the need for separate control signals and simplifying the overall control structure while using only P-type transistors
Solution Approach 2:
The storage capacitor in the patent serves multiple functions: it stores the pixel data voltage, enables threshold voltage compensation through discharge, and acts as a reset mechanism. This multi-functionality reduces the number of required control signals and simplifies the circuit while maintaining ease of manufacture with P-type transistors only
3Manufacturing precision
If separate scanning signals are used for reset and writing compensation operations, then manufacturing precision is improved, but ease of operation deteriorates
Solution Approach 1:
The patent merges the reset operation and threshold compensation operation into a single unified process. One scanning signal controls the simultaneous discharge of the capacitor for both reset and compensation purposes, eliminating the need for separate scanning signals while maintaining precise threshold voltage compensation and improving ease of operation
Data Source
AI summary
The present disclosure provides a display device, a display panel and a pixel driving circuit. The pixel driving circuit includes a driving transistor, a first scanning terminal, a second scanning terminal, a data input terminal, a light emission control terminal, a storage capacitor, a reset unit, and a write compensation unit and a light emission control unit, wherein the reset unit is turned on according to a first scanning signal from the first scanning terminal to reset the storage capacitor and charge the storage capacitor; and the writing compensation unit is turned on according to a second scanning signal from the second scanning terminal, to cause data signals provided by the data input terminal to be written into a gate electrode of the driving transistor, and to cause the storage capacitor to be discharged through the writing compensation unit and the driving transistor until the driving transistor is turned off.