Non-Parallel Comb Color Filter Pair for Robust Light Mixing

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Solution Overview

Problem

Existing color mixing systems for light fixtures with multiple light sources, such as LEDs, are not robust or tolerant enough, requiring precise alignment and increasing manufacturing costs and reliability issues due to misalignment caused by temperature changes and external forces.

Innovation Solution

A color filter pair with non-parallel elongated teeth that can be moved linearly in parallel planes, allowing for partial overlap and reducing sensitivity to misalignment, ensuring consistent color mixing even with multiple light sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If color filters with parallel comb-like structures are used for precise color mixing, then color mixing accuracy is improved, but manufacturing precision requirements increase and alignment sensitivity worsens

Engineering Contradiction:
Improvecolor mixing accuracyVSAvoidalignment precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent applies asymmetry by designing the comb-like structures of the two color filters with different tooth configurations. Specifically, the first color filter has teeth with a first pitch and the second color filter has teeth with a second pitch that differs from the first pitch. This asymmetric design breaks the perfect parallel alignment requirement, making the system more tolerant to manufacturing variations and alignment errors while still achieving effective color mixing through the intentional mismatch pattern.

Inventive Principle:
Principle #4Asymmetry

2Measurement precision

If color filters are designed with parallel comb-like structures, then color mixing effectiveness is improved, but reliability under temperature changes and external forces worsens

Engineering Contradiction:
Improvecolor mixing effectivenessVSAvoidalignment stability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The asymmetric tooth pitch design creates a color mixing system that is inherently more reliable under varying conditions. When temperature changes or external forces cause slight shifts in filter positions, the asymmetric configuration ensures that the overlapping pattern still produces effective color mixing, unlike parallel structures where even small misalignments can significantly degrade performance.

Inventive Principle:
Principle #4Asymmetry

3Measurement precision

If parallel comb-like color filters are used, then color mixing performance is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvecolor mixing performanceVSAvoidalignment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The asymmetric design simplifies the overall device complexity by eliminating the need for extremely precise alignment mechanisms. The different tooth pitches naturally create a robust overlapping pattern that maintains color mixing performance without requiring complex alignment systems, thereby reducing manufacturing complexity and cost.

Inventive Principle:
Principle #4Asymmetry

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 provides a more robust and reliable color mixing system that maintains consistent color output despite misalignment, reducing manufacturing complexity and enhancing reliability in light fixtures with multiple light sources.

Implementation Method 1

In subtractive color mixing a number of color filters is inserted into the light beam from at least one light source and the color filter subtracts optical wavelengths from the light beam in order to create a certain color

Methodology Applied
Scientific EffectSubtractive color mixing: Absorption (EM radiation)

Data Source

PatentEP3457023B1Color filter pair with comb-like filter characteristics having non-parallel teeth
Publication Date: 2020.03.04 MARTIN PROFESSIONAL
  • EP3457023B1 patent drawingFigure 1A~1B'
  • EP3457023B1 patent drawingFigure 1A''~1B'''
  • EP3457023B1 patent drawingFigure 2A~3B

AI summary

A filter assembly with a color filter pair for a light fixture comprising two color filters is provided, where the color filters are linear moveable relatively to each other in parallel planes by at least one actuator. Each of the colors filters comprise a color filtering region formed as a comb-like structure comprising plurality of elongated teeth where the elongated teeth of the color filters are angled in relation to the direction of movement of the color filters. Further, the angle between the elongated teeth of the same color filter is less than 10 degrees and the elongated teeth of the two color filters are non-parallel in relation to each other. A light fixture comprising a plurality of such color filter pairs is also described.