Light Emitting Display Pixel Compensation for MPRT Clarity

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Solution Overview

Problem

In light emitting display apparatuses, the delay in motion picture response time (MPRT) leads to unclear images due to inconsistent black image display across pixels, caused by varying degrees of degradation in driving transistors and distortion of reference voltages.

Innovation Solution

A light emitting display apparatus that generates black image data voltages based on characteristic values of each pixel, including threshold voltage variations, to ensure uniform black image display and reduce reference voltage distortion, thereby maintaining image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the same black image data voltage is supplied to all pixels, then the reference voltage line can be kept simple, but dimming occurs in portions of the display due to varying transistor degradation

Engineering Contradiction:
Improvereference voltage line complexityVSAvoidblack image display uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by setting different black image data voltages for different pixels based on their individual characteristics. Specifically, the black image data voltage for each pixel is adjusted according to the threshold voltage of its driving transistor, ensuring that each pixel receives a customized voltage that compensates for its specific degradation level. This resolves the contradiction by maintaining uniform black image display across the panel without requiring complex reference voltage line modifications.

Inventive Principle:
Principle #3Local quality

2Productivity

If a black image data voltage is supplied to a data line, then the black image can be displayed, but the reference voltage supplied through the parallel reference voltage line is shaken (distorted)

Engineering Contradiction:
Improveblack image display capabilityVSAvoidreference voltage stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent introduces a compensation mechanism that acts as an intermediary between the data line voltage changes and the reference voltage. By detecting the voltage change in the data line when black image data is supplied and applying an equal and opposite voltage change to the reference voltage line, the system cancels out the coupling effect. This mediator approach maintains both the black image display capability and the reference voltage stability simultaneously.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the reference voltage is shaken, then the voltage at the source of the driving transistor is shaken, but normal image display is maintained

Engineering Contradiction:
Improveimage display functionalityVSAvoidvoltage stability
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent implements a feedback mechanism where the actual voltage state of the data line is continuously monitored, and based on this feedback, the reference voltage is dynamically adjusted. When black image data voltage is supplied causing a voltage change in the data line, the system detects this change and applies a compensating voltage to the reference voltage line. This closed-loop feedback ensures that the reference voltage remains stable despite voltage fluctuations in the data line, maintaining both functionality and precision.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3675109B1Light emitting display apparatus
Publication Date: 2023.11.29 LG DISPLAY CO LTD
  • EP3675109B1 patent drawingFigure 1
  • EP3675109B1 patent drawingFigure 2~3
  • EP3675109B1 patent drawingFigure 4~5

AI summary

Disclosed is a light emitting display apparatus which sets black image data, corresponding to a black image (BI) displayed after a normal image (I) is displayed, for each pixel in one frame period on the basis of a characteristic of a light emitting display panel.