Series OLED Pixel Structure for Display Panel Voltage Drop Reduction

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Solution Overview

Problem

In large organic light emitting display apparatuses, the increasing wiring resistance due to larger active matrix driving circuits leads to voltage drops that result in heat power consumption, reducing electrical-optical efficiency and affecting display performance.

Innovation Solution

The implementation of at least two organic light emitting diodes connected in series within each pixel structure, sharing voltage and reducing the driving current, thereby minimizing wiring voltage drop and heat power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the size of the organic light emitting display apparatus increases, then the display area is improved, but the wiring resistance increases causing voltage drop and heat power consumption

Engineering Contradiction:
Improvedisplay areaVSAvoidheat power consumption
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The light emitting device is divided into multiple sub-light emitting devices connected in series (e.g., first, second, third sub-light emitting devices). This segmentation allows the total voltage to be distributed across multiple components, reducing the current required for a given power output. Since heat power consumption is proportional to the square of the current (P=I²R), reducing current significantly reduces energy loss in the wiring resistance.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a single voltage source VDD-VSS is used to drive all pixels, then the circuit complexity is reduced, but the voltage drop and heat power consumption increase

Engineering Contradiction:
Improvecircuit complexityVSAvoidheat power consumption
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The pixel circuit is segmented into multiple driving transistors (first, second, third driving transistors) that control different sub-light emitting devices. This allows independent optimization of voltage distribution across different parts of the circuit, reducing the overall current requirement and thereby reducing heat power consumption while maintaining manageable circuit complexity through modular design.

Inventive Principle:
Principle #1Segmentation

3Illumination intensity

If the driving current is increased to compensate for voltage drop, then the light emitting performance is improved, but the heat power consumption increases

Engineering Contradiction:
Improvelight emitting performanceVSAvoidheat power consumption
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

By segmenting the light emitting device into multiple sub-devices connected in series, the patent achieves the desired light emitting performance through distributed voltage application rather than high current. Each sub-device receives an appropriate voltage portion, maintaining overall luminance while the reduced current minimizes I²R losses in the wiring.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the electrical parameters by increasing the operating voltage and reducing the operating current. Since power P=VI, increasing voltage while proportionally decreasing current maintains the same power output to the light emitting device, but the reduced current significantly lowers the power loss in the wiring resistance (Ploss=I²R).

Inventive Principle:
Principle #35Parameter changes

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

This approach significantly reduces useless heat power consumption and increases the electrical-optical efficiency of the display apparatus by lowering the driving current and heat dissipation, while maintaining the same driving power.

Implementation Method 1

at least two organic light emitting diodes connected in series within each pixel structure, sharing voltage and reducing the driving current

Methodology Applied
Scientific EffectSeries connection electrical principle: Ohm's Law

Implementation Method 2

minimizing wiring voltage drop and heat power consumption... reduces useless heat power consumption... lowering the driving current and heat dissipation

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2743909B1Pixel structure, pixel unit structure, display panel and display apparatus
Publication Date: 2018.05.02 BOE TECHNOLOGY GROUP CO LTD
  • EP2743909B1 patent drawingFigure 1
  • EP2743909B1 patent drawingFigure 2
  • EP2743909B1 patent drawingFigure 3

AI summary

The embodiment of the present invention provides a pixel structure, pixel unit structure, display panel and display apparatus, which is used to increase the electrical-optical efficiency of the display apparatus. The pixel structure includes an active matrix driving circuit, also includes at least two light emitting devices connected in series which are connected to the active matrix driving circuit, the light emitting devices compose the light emitting device group, and the active matrix driving circuit drives the light emitting devices to emit light.