Video Wall LED Driver Compensation for Luminance Uniformity

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Solution Overview

Problem

Existing image display apparatuses using passive-matrix driven light emitting diode panels experience luminance non-uniformity due to coupling noise generated by data signal output, especially when different numbers of light emitting diodes are driven by respective data driving integrated circuits.

Innovation Solution

Incorporating a coupling compensator between the current source and the light emitting diode, which outputs a compensation signal to counteract coupling noise based on the switch's turn-on or turn-off, and using a data driving integrated circuit with a current source and switch to maintain luminance uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple data driving integrated circuits are used to drive light emitting diodes, then the driving capability is improved, but coupling noise is generated causing luminance non-uniformity

Engineering Contradiction:

Improvedriving capabilityVSAvoidcoupling noise

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful coupling noise into a useful compensation signal. The coupling compensator detects the coupling noise generated by switch switching and generates a compensation signal with opposite polarity to cancel out the noise, thereby maintaining luminance uniformity while enabling multi-IC driving capability

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The coupling compensator acts as an intermediary component between the data driving integrated circuit and the light emitting diode. It introduces a compensation signal through a dedicated compensation line to mediate the harmful interaction caused by coupling noise, allowing the system to maintain both high driving capability and luminance uniformity

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the number of light emitting diodes driven by respective data driving integrated circuits is different, then the system flexibility is improved, but luminance uniformity deteriorates

Engineering Contradiction:

Improvesystem flexibilityVSAvoidluminance uniformity

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The coupling compensator implements a feedback mechanism by continuously monitoring the switching state of the switch and generating real-time compensation signals. This feedback loop ensures that luminance uniformity is maintained regardless of variations in the number of light emitting diodes driven by different data driving integrated circuits, providing both flexibility and precision

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12586517B2Image display apparatus, and video wall including the same

Publication Date: 2026.03.24 LG ELECTRONICS INC

AI summary

The image display apparatus and a video wall including the same according to an embodiment of the present disclosure includes: a panel including a plurality of light emitting diodes; a scan driver to output a scan signal; a data driver to output a data signal; and a controller to control the data driver, and the data driver includes a plurality of data driving integrated circuits, and the data driving integrated circuit includes a current source, a switch disposed between the current source and the light emitting diode, and a coupling compensator to output a compensation signal for compensating coupling noise caused based on turn-on or turn-off of the switch. Accordingly, luminance uniformity between the plurality of light emitting diodes may be maintained.