Multi-Channel Lighting Circuit with Leakage Paths for Color Control

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Solution Overview

Problem

Existing multi-channel lighting circuits face inefficiencies in maintaining color consistency and flux variation, requiring significant calibration processes and data transfer, which limits flexibility and increases computational load.

Innovation Solution

A lighting circuit with a series connection of lighting channels, each comprising an LED arrangement and a current leakage path in parallel, bypassing current to equalize light output across channels, eliminating the need for calibration and data transfer by using shunt switches for flux control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If shunt switching with PWM signals is used to control multi-channel lighting circuits, then color consistency is maintained across channels, but significant calibration processes and data transfer are required between L2 board and controller

Engineering Contradiction:
Improvecolor consistencyVSAvoidcalibration process complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The system performs self-calibration by automatically measuring LED characteristics and storing bin information in the L2 board's memory. This eliminates the need for external calibration processes and manual data transfer, as the system independently characterizes and compensates for LED variations.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The controller reads LED bin information from the L2 board and uses this feedback to adjust PWM duty cycles for each channel. This closed-loop approach ensures color consistency is maintained while eliminating manual calibration, as the system continuously adapts based on actual LED characteristics.

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If LED characteristics are recorded and managed with data transfer between L2 board and controller, then color compensation is achieved, but significant additional data storage, handling and processing requirements are created

Engineering Contradiction:
Improvecolor compensationVSAvoiddata storage requirements
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

LED bin information is measured and stored in the L2 board's memory during manufacturing or initial setup, before the system enters normal operation. This preliminary characterization eliminates the need for continuous data transfer and processing during operation, as all necessary compensation data is already available locally.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If multiple L2 boards are connected in parallel with the same shunt switches, then system scalability is improved, but color compensation cannot be implemented at the individual board level

Engineering Contradiction:
Improvesystem scalabilityVSAvoidcolor compensation capability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The system divides color compensation functionality into independent segments at each L2 board level. Each board has its own shunt switches and LED bin information storage, enabling individual boards to be calibrated and compensated independently while maintaining overall system scalability and flexibility.

Inventive Principle:
Principle #1Segmentation

4Measurement precision

If calibration measurement is performed to determine LED bin characteristics, then accurate color compensation is achieved, but costly measurement processes are required

Engineering Contradiction:
ImproveLED bin characterization accuracyVSAvoidcalibration cost
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The system performs self-calibration using built-in measurement capabilities, eliminating the need for external costly calibration equipment and services. The L2 board automatically measures and stores LED characteristics, providing accurate bin information at minimal cost.

Inventive Principle:
Principle #25Self-service

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

The solution ensures energy-efficient operation with consistent color points across varying brightness levels without the need for calibration, allowing independent replacement of lighting boards and reducing computational demands.

Implementation Method 1

each lighting channel comprises: an LED arrangement; and a current leakage path in parallel with the LED arrangement, wherein each current leakage path is arranged to bypass a current from the corresponding LED arrangement

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentEP4295647B1Lighting circuit
Publication Date: 2025.07.02 SIGNIFY HOLDING BV
  • EP4295647B1 patent drawingFigure 1
  • EP4295647B1 patent drawingFigure 2
  • EP4295647B1 patent drawingFigure 3

AI summary

A lighting circuit has a series connection of a plurality of lighting channels of different output colors, driven by a current source. Some or all of the lighting channels comprise a LED arrangement, a shunt switch in parallel with the LED arrangement and a current leakage path in parallel with the LED arrangement. The current leakage path is used to calibrate the current flowing through the LED arrangement and thereby take account of the LED characteristics.