Ripple-Based LED Driver for Flicker Reduction

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Solution Overview

Problem

Existing LED drivers fail to effectively reduce flickering caused by ripple fluctuations in light intensities produced by LED circuits, which is annoying and requires additional power dissipating or feedback components.

Innovation Solution

A driver system that generates control signals based on ripple information to control the intensities of first and second LED circuits, ensuring their sum has reduced or no fluctuations, without requiring additional power dissipating regulators or optical feedback, by using generators and controllers to manage the LED intensities in anti-phase with the ripple.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If additional power dissipating regulators or optical feedback components are used to reduce flickering, then the flickering reduction effectiveness is improved, but the device complexity and power loss increase

Engineering Contradiction:
ImproveflickeringVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The LED lighting system is divided into multiple independent LED circuits (first LED circuit, second LED circuit, etc.), each driven by separate control signals. This segmentation allows independent control of each circuit's intensity to compensate for ripple effects, reducing flickering without requiring complex feedback components for the entire system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control signals are designed with preliminary anti-phase characteristics relative to the ripple frequency. By generating control signals that anticipate and counteract the ripple-induced intensity fluctuations before they manifest as visible flickering, the system reduces harmful effects without needing reactive feedback components.

Inventive Principle:
Principle #9Preliminary anti-action

2Object-affected harmful factors

If additional power dissipating regulators are used to reduce flickering, then the flickering reduction effectiveness is improved, but the energy loss increases

Engineering Contradiction:
ImproveflickeringVSAvoidenergy loss
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The system dynamically adjusts the intensity of individual LED circuits based on real-time control signals that are phase-modulated to counteract ripple effects. This dynamic control allows the system to maintain stable perceived light output without the continuous power dissipation required by traditional linear regulators.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control signals modify operating parameters (intensity, phase timing) of individual LED circuits to compensate for ripple-induced fluctuations. By changing these parameters dynamically rather than using fixed resistance-based regulation, the system reduces energy loss while maintaining stable light output.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3092871B1Ripple based light emitting diode driving
Publication Date: 2020.03.18 SIGNIFY HOLDING BV
  • EP3092871B1 patent drawingFigure 1~2
  • EP3092871B1 patent drawingFigure 3~5

AI summary

Drivers (10) for driving first and second light emitting diode circuits (1, 2) that produce first and second light may comprise first generators (11) for in response to ripple information generating first control signals and first controllers (12) for in response to the first control signals controlling first intensities of the first light such that a sum of the first and second intensities the first and second light is less fluctuating than each one of these intensities. The ripple information defines parameters of ripples resulting from rectifications of alternating-current signals. The drivers (10) may further comprise second generators (21) for in response to the ripple information generating second control signals and second controllers (22) for in response to the second control signals controlling the second intensities. Ripple based flickering is reduced and smaller capacitors can be used.