OLED Power Supply Voltage Compensation for Crosstalk Reduction

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Solution Overview

Problem

Existing display devices face issues with horizontal crosstalk and abnormal screens due to significant voltage variations caused by load changes, particularly in organic light emitting diode (OLED) panels with numerous thin film transistors, where predicting and mitigating these variations is challenging.

Innovation Solution

A display device and driving method that incorporate a power supply unit with a current amount analyzing unit, variation determining unit, and output voltage varying unit to predict and compensate for output voltage variations based on data and synchronization signals, applying rise and fall compensation voltages before load changes occur, thereby stabilizing the output voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the power supply unit outputs voltage to drive the display panel with numerous TFTs, then the display device can achieve high resolution and advanced functionality, but significant voltage variations occur due to load changes causing horizontal crosstalk and abnormal screens

Engineering Contradiction:
Improvedisplay resolution and functionalityVSAvoiddisplay quality stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The power supply unit performs a compensation operation to vary the output voltage before the load is changed. The timing controller generates a leading compensation signal in advance of the load variation, enabling the power supply unit to adjust the output voltage proactively to counteract upcoming load changes and prevent voltage wavering that causes horizontal crosstalk and abnormal screens

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism where the timing controller monitors synchronization signals and generates compensation signals based on detected load variation patterns. This feedback loop enables the power supply unit to continuously adjust the output voltage in response to load changes, maintaining stable voltage levels despite variations in display panel loading

Inventive Principle:
Principle #23Feedback

2Reliability

If additional capacitors are added to the power supply unit to stabilize output voltage, then horizontal crosstalk can be reduced, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveoutput voltage stabilityVSAvoidpower supply unit structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention replaces the traditional passive electrical approach (adding capacitors for voltage stabilization) with an active control system. The timing controller generates compensation signals that actively regulate the output voltage, substituting the need for additional passive components like capacitors and reducing overall system complexity while maintaining voltage stability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The power supply unit dynamically changes the output voltage parameter in response to compensation signals from the timing controller. By actively adjusting the voltage parameter based on detected load variations, the system achieves stable output without requiring additional capacitive components, thereby simplifying the power supply unit structure

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3038093B1Display device and driving method thereof
Publication Date: 2019.06.26 LG DISPLAY CO LTD
  • EP3038093B1 patent drawingFigure 1~2
  • EP3038093B1 patent drawingFigure 3~4
  • EP3038093B1 patent drawingFigure 5~6

AI summary

A display device includes a display panel, a driver, a power supply unit, and a timing controller. The power supply unit may supply a voltage to the driver. The power supply unit may perform a compensation operation to vary an output voltage output from the power supply unit itself to correspond to a variation of a load before the load is varied.