OLED Display Repair via Dummy Pixel Coupling

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Solution Overview

Problem

In organic light emitting display apparatuses, defective pixels can become bright spots due to constant light emission, which are highly visible and difficult to repair without affecting the display's overall appearance.

Innovation Solution

The apparatus includes emission pixels, dummy pixels, and repair lines, where defective pixels are electrically isolated and coupled to dummy pixels through repair lines, allowing for the application of data signals and driving currents to normalize their light emission, reducing the visibility of bright or dim spots.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a defective pixel is left unrepaired, then the manufacturing process is simpler and faster, but the display quality deteriorates due to visible bright spots

Engineering Contradiction:
Improvemanufacturing yieldVSAvoiddisplay quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

Dummy pixels are pre-configured in the display panel during manufacturing, ready to receive and drive defective emission pixels when needed. This preliminary preparation allows rapid repair without affecting manufacturing yield, as the repair mechanism is already in place before defects occur.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A repair line is introduced as an intermediary connection that couples the defective emission pixel to a dummy pixel. This repair line acts as a mediator, transferring the driving signal from the dummy pixel to the defective emission pixel, thereby enabling repair while maintaining display quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a defective pixel is converted from bright spot to dim spot, then the defect is less visible, but the overall display appearance deteriorates

Engineering Contradiction:
Improvevisibility of defectVSAvoiddisplay appearance
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

Instead of changing the defect from bright spot to dim spot, the invention changes the driving parameters of the defective pixel by connecting it to a dummy pixel through a repair line. This allows the defective pixel to be driven with appropriate signals that normalize its light emission, making it indistinguishable from normal pixels and thus eliminating the defect visibility issue while maintaining display appearance.

Inventive Principle:
Principle #35Parameter changes

3Ease of repair

If repair lines are added to couple emission pixels to dummy pixels, then defective pixels can be repaired, but the device complexity increases

Engineering Contradiction:
Improvedefect repair capabilityVSAvoidcircuit structure
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

Dummy pixels are designed to serve multiple functions: they act as normal display pixels during normal operation and simultaneously serve as repair sources for defective emission pixels. This multi-functionality allows the repair mechanism to be integrated without adding separate dedicated repair circuits, thereby minimizing the increase in device complexity while maintaining ease of repair.

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

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 method effectively reduces the visibility of defective pixels by allowing them to emit light at a normal level, improving the display's appearance and manufacturing yield without converting bright spots into dim spots.

Implementation Method 1

a plurality of emission pixels arranged in a matrix of a plurality of rows and a plurality of columns, wherein the emission pixels each include an organic light emitting diode (OLED)

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2876683B1Organic light emitting display apparatus and method of repairing the same
Publication Date: 2017.05.10 SAMSUNG DISPLAY CO LTD
  • EP2876683B1 patent drawingFigure 1
  • EP2876683B1 patent drawingFigure 2
  • EP2876683B1 patent drawingFigure 3

AI summary

An organic light emitting display apparatus (100) includes: a plurality of emission pixels (EPij, EPi+1,j) arranged in a matrix of a plurality of rows and a plurality of columns, wherein the emission pixels (EPij, EPi+1,j) each comprise a light emitting diode (LED) (E); a plurality of dummy pixels (DPj, DPj+1); a plurality of repair lines (V.RLi, V.RLi+1), wherein at least one (EPij) of the plurality of emission pixels is coupled to at least one (DPj) of the plurality of dummy pixels through one (V.RLj) of the repair lines; and at least one auxiliary repair line (H.RLi) coupling at least two (V.RLj, V.RLj+1) of the plurality of repair lines.