OLED Pixel Compensation Circuit for High Resolution Displays

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Solution Overview

Problem

OLED display panels face challenges in achieving high resolution due to the area occupied by driving circuits in compensation pixel circuits, which limits the improvement of display uniformity and resolution.

Innovation Solution

A compensation pixel circuit that collects the gate voltage of the driving transistor and compensates surrounding non-compensation pixel circuits, reducing the number and area of compensation driving circuits, thereby improving resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If compensation driving circuits are added to each pixel circuit to compensate for threshold voltage drift, then display uniformity is improved, but the area occupied by driving circuits increases and resolution is limited

Engineering Contradiction:
Improvedisplay uniformityVSAvoidarea occupied by driving circuits
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges the compensation function into the existing pixel circuit by sharing the driving transistor between normal display pixels and compensation pixels. The same driving transistor serves dual purposes: driving OLEDs in normal pixels and performing threshold voltage compensation in compensation pixels, thereby eliminating the need for separate compensation driving circuits and reducing overall circuit area.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The driving transistor is designed with multi-functionality, serving both as the drive transistor for OLED illumination in normal pixel circuits and as the compensation transistor for threshold voltage compensation in compensation pixel circuits. This universal design allows one transistor to perform multiple functions, reducing the total number of transistors and circuit area.

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

2Measurement precision

If more compensation driving circuits are used to improve display uniformity, then compensation precision is improved, but device complexity increases

Engineering Contradiction:
Improvecompensation precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the compensation measurement and compensation execution functions into a single pixel circuit using the same driving transistor. The compensation pixel circuit shares all critical components (driving transistor, storage capacitor, OLED) with the normal pixel circuit, thereby achieving precise threshold voltage compensation without adding complex separate compensation circuits.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pixel circuit performs self-compensation by using its own driving transistor to measure and compensate for threshold voltage drift. The compensation pixel circuit utilizes the same components to generate compensation signals that correct the threshold voltage, enabling the system to self-correct without external intervention or additional complex compensation mechanisms.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3499492B1Pixel compensation circuit, display panel, display device, and compensation and drive methods
Publication Date: 2022.11.16 BOE TECHNOLOGY GROUP CO LTD
  • EP3499492B1 patent drawingFigure 1(a)~1(b)
  • EP3499492B1 patent drawingFigure 2(a)~2(b)
  • EP3499492B1 patent drawingFigure 3~4

AI summary

A compensation pixel circuit, a display panel, a display apparatus, a regional compensation method and a driving method are provided. The compensation pixel circuit (100) includes a compensation driving circuit (110) and a signal acquiring circuit (120) connected with the compensation driving circuit (110). The compensation driving circuit (110) includes a driving transistor and an organic light-emitting diode. The compensation driving circuit (110) is configured to receive a light-emitting data signal, compensate a threshold voltage of the driving transistor, and drive the organic light-emitting diode to illuminate in accordance with the light-emitting data signal. The signal acquiring circuit (120) is configured to acquire a gate voltage of the driving transistor. Threshold voltage compensation can be realized by collecting the gate voltage of the driving transistor in the compensation pixel circuit and compensating the surrounding non-compensation pixel circuits based on the voltage. This arrangement reduces the number of compensation driving circuits and the area on the panel occupied by the driving circuits, facilitating improvement of the resolution of the display panel.