AMOLED Pixel Driving Circuit for Faster Response and Uniform Black Display

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Solution Overview

Problem

The existence of a storage capacitor in AMOLED pixel driving circuits leads to longer charging times and delayed luminescence, slowing down the response speed of the display panel due to coupling capacitance.

Innovation Solution

A pixel driving circuit design that includes a driving transistor, storage capacitor, and response switches, utilizing a trigger to generate control signals to initialize the driving transistor and reduce coupling capacitance, ensuring uniform black display and improved response speed by disconnecting the light emitting unit from external influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a storage capacitor is arranged in the pixel driving circuit, then the transistor can be driven to generate a coupling capacitor for maintaining voltage, but the charging time becomes longer and the response speed slows down

Engineering Contradiction:
Improvevoltage maintenanceVSAvoidresponse speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent applies preliminary action by initializing the driving transistor before the light emitting unit is driven. The trigger circuit generates control signals that activate response switches to initialize the driving transistor in advance, ensuring it is in the correct state before operation begins. This preliminary initialization reduces the charging time required during actual operation and improves response speed while maintaining the voltage maintenance function of the storage capacitor.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If the driving transistor is not initialized, then the circuit operation is simpler, but the black display uniformity deteriorates and flickering occurs

Engineering Contradiction:
Improvecircuit complexityVSAvoidblack display uniformity
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent merges the initialization function with the existing trigger circuit by using the same trigger signal to control response switches that initialize the driving transistor. This integration allows the initialization operation to be performed using existing circuit components and control signals, minimizing additional circuit complexity while achieving uniform black display and preventing flickering.

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If additional initialization circuits are added, then the black display uniformity improves, but the device complexity increases

Engineering Contradiction:
Improveblack display uniformityVSAvoidcircuit complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The response switches in the patent serve multiple functions: they initialize the driving transistor when activated by the trigger circuit, and they can also control the connection between the light emitting unit and external circuits. This multi-functionality allows the initialization capability to be added without proportionally increasing device complexity, as the same switches perform both initialization and circuit connection control functions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4418251B1Pixel driving circuit and driving method therefor, and display apparatus
Publication Date: 2025.12.03 HKC CORP LTD
  • EP4418251B1 patent drawingFigure 1
  • EP4418251B1 patent drawingFigure 2
  • EP4418251B1 patent drawingFigure 3~4

AI summary

The application provides a pixel driving circuit, a driving method thereof and a display panel (40). The pixel driving circuit comprises a driving transistor (T0), a storage capacitor (C), a trigger (U1), a first response switch (T1) and a second response switch (T2). A first terminal of the driving transistor (T0) is connected to a power source (10), a second terminal of the driving transistor (T0) is connected to a light emitting unit (20), and a control terminal of the driving transistor is connected to a first terminal of the storage capacitor (C), and a second terminal of the storage capacitor (C) is connected to the power source (10). A first terminal of the first response switch (T1) is connected to a data line (data), a control terminal of the first response switch (T1) is connected to a scan line (scan), a second terminal of the first response switch (T1) is connected to the first terminal of the storage capacitor (C), an input terminal of the trigger (U1) is connected to the scan line (scan), a first terminal of the second response switch (T2) is connected to the second terminal of the drive transistor (T0), a second terminal of the second response switch (T2) is connected to an initial voltage terminal (30), and a control terminal of the second response switch (T2) is connected to an output terminal of the trigger (U1).