OLED Pixel Circuit Hybrid Electrical Optical Compensation

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Solution Overview

Problem

The existing OLED display devices face issues with brightness uniformity due to differences in threshold voltages and mobility of driving transistors, leading to regional brightness deviations and patterns, which are not effectively addressed by either electrical or optical compensation methods alone.

Innovation Solution

A pixel circuit that combines electrical and optical compensation circuits to detect and adjust the brightness of OLED display panels, using a driving circuit, data writing circuit, storage circuit, electrical compensation circuit, and optical compensation circuit to achieve real-time compensation for brightness uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If electrical compensation method is used, then threshold voltage differences are compensated, but mobility differences and aging effects are not effectively addressed

Engineering Contradiction:
Improvebrightness uniformityVSAvoidcompensation coverage
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent combines electrical compensation circuit and optical compensation circuit into a hybrid compensation system. The electrical compensation circuit compensates for threshold voltage differences, while the optical compensation circuit compensates for mobility differences and aging effects. By merging these two compensation methods, the system achieves comprehensive compensation for all three factors, resolving the limitation of electrical compensation alone.

Inventive Principle:
Principle #5Merging (Combining)

2Manufacturing precision

If optical compensation method is used, then mobility differences and aging effects are compensated, but threshold voltage differences are not effectively addressed

Engineering Contradiction:
Improvebrightness uniformityVSAvoidcompensation coverage
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent integrates optical compensation circuit with electrical compensation circuit to form a hybrid system. The optical compensation circuit specifically addresses mobility differences and aging effects through optical feedback, while the electrical compensation circuit handles threshold voltage differences. This merging allows each circuit to address its specific strength area without leaving gaps.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If only electrical compensation circuit is used, then circuit structure is simple, but brightness uniformity is insufficient

Engineering Contradiction:
Improvecircuit structureVSAvoidbrightness uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent merges electrical compensation circuit and optical compensation circuit into a coordinated hybrid system. The electrical compensation circuit provides baseline compensation for threshold voltage with simpler structure, while the optical compensation circuit adds compensation for mobility and aging effects. The combination achieves superior brightness uniformity while maintaining reasonable circuit complexity through functional division.

Inventive Principle:
Principle #5Merging (Combining)

4Manufacturing precision

If only optical compensation circuit is used, then compensation for mobility and aging is achieved, but overall brightness uniformity is insufficient

Engineering Contradiction:
Improvebrightness uniformityVSAvoidcircuit structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines optical compensation circuit and electrical compensation circuit in a hybrid architecture where each circuit type addresses specific compensation needs. The optical compensation circuit handles mobility and aging compensation, while the electrical compensation circuit handles threshold voltage compensation. This division of labor achieves comprehensive brightness uniformity while managing circuit complexity through specialized functional modules.

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The combined electrical and optical compensation method significantly improves the uniformity of display brightness and overall display effect by compensating for differences in threshold voltages and mobility, as well as aging effects, resulting in enhanced real-time performance.

Implementation Method 1

an optical compensation circuit, configured to detect light emitted by the light emitting element in response to an optical detection enable signal, and apply an electrical signal, which is generated according to the light emitted by the light emitting element, to a second detecting terminal

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP3779948B1Pixel circuit and driving method therefor, and display panel
Publication Date: 2023.10.04 BOE TECHNOLOGY GROUP CO LTD
  • EP3779948B1 patent drawingFigure 1~2
  • EP3779948B1 patent drawingFigure 3~4
  • EP3779948B1 patent drawingFigure 5~6

AI summary

A pixel circuit and a driving method thereof, and a display panel are provided. The pixel circuit (10) includes a driving circuit (100), a data writing circuit (200), a storage circuit (300), an electrical compensation circuit (500), and an optical compensation circuit (600). The driving circuit (100) controls a driving current that drives a light emitting element (400) to emit light. The data writing circuit (200) writes a data signal to a control terminal (130) of the driving circuit (100) in response to a scanning signal. A first terminal and a second terminal of the storage circuit (300) are respectively connected to the control terminal (130) and a second terminal (120) of the driving circuit (100), and the storage circuit (300) is used for storing the data signal. The electrical compensation circuit (500) is connected to the second terminal (120) of the driving circuit (100), and electrically connects the second terminal (120) of the driving circuit (100) to a first detecting terminal (SI) in response to an electrical detection enable signal. The optical compensation circuit (600) applies an electrical signal, which is generated according to the light emitted from the light emitting element (400), to the second detecting terminal (S2) in response to an optical detection enable signal. The pixel circuit can compensate for brightness uniformity.