Phosphor Layer for Enhanced Color Contrast in Lamps

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Fluorescent lighting struggles to provide enhanced color contrast without reducing light output, as filtration methods like neodymium glass tend to decrease luminosity, which is acceptable in incandescent lamps but not in other lighting sources.

Innovation Solution

A lamp with a phosphor layer comprising specific phosphors such as Yttrium Oxide:Eu and (Ba,Sr,Ca)MgAl10O17:Eu2+,Mn2+, which emits light with a correlated color temperature between 2000 to 3500 Kelvin and a color quality scale Qa value of 60 or above, achieving enhanced color contrast without the need for filtration or decreased lumen output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If neodymium glass filtration is used to enhance color contrast, then red-green color contrast is improved, but light output is reduced

Engineering Contradiction:
Improvecolor contrastVSAvoidlumen output
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent changes the spectral parameters by using phosphors with specific emission characteristics (red phosphor with peak 610-680nm and green phosphor with peak 500-570nm) to directly generate enhanced color contrast without filtration, thereby avoiding lumen loss while achieving the desired color rendering

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite phosphor system combining multiple phosphor materials (red phosphor and green phosphor) to create a synergistic effect that produces enhanced color contrast. This composite approach allows simultaneous optimization of color rendering and light output by leveraging the complementary emission spectra of different phosphors

Inventive Principle:
Principle #40Composite materials

2Use of energy by moving object

If fluorescent lighting is used for energy efficiency, then energy consumption is reduced, but color rendering is muted

Engineering Contradiction:
Improveenergy efficiencyVSAvoidcolor rendering
Core Design Contradiction:
Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent optimizes the phosphor emission parameters (peak wavelengths and half-value widths) to generate a spectral power distribution that closely mimics incandescent lighting, achieving superior color rendering (CQS Qa≥60) while maintaining the energy efficiency of fluorescent technology through controlled phosphor conversion

Inventive Principle:
Principle #35Parameter changes

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 lamp produces light with improved color contrast, similar to neodymium glass-filtered incandescent sources, while maintaining sufficient brightness, by using a blend of phosphors that enhance the red-green color contrast and reproduce desirable spectra characteristics without the drawbacks of filtration methods.

Implementation Method 1

a phosphor layer comprising a phosphor composition. The composition comprises a first phosphor and a second phosphor

Methodology Applied
Scientific EffectPhosphorescence: Phosphorescence

Implementation Method 2

The first phosphor has an emission band with a maximum between about 610 nm and about 680 nm; The second phosphor has an emission band with a maximum between about 500 nm and about 570 nm

Methodology Applied
Scientific EffectLight absorption and emission: Absorption (EM radiation)

Implementation Method 3

a discharge-sustaining fill sealed inside the envelope

Methodology Applied
Scientific EffectElectrical discharge: Electric Arc

Data Source

PatentEP2210264B1Enhanced color contrast light source
Publication Date: 2019.11.27 GENERAL ELECTRIC CO
  • EP2210264B1 patent drawingFigure 1
  • EP2210264B1 patent drawingFigure 2
  • EP2210264B1 patent drawingFigure 3

AI summary

A lamp having improved color quality scale is provided. The lamp has a light- transmissive envelope and a phosphor layer comprising a first phosphor and a second phosphor wherein the first phosphor has an emission band with a maximum between 590 nm and 670 nm and the second phosphor has an emission band with a maximum between 520 nm and 570 nm. The light generated by the phosphor layer, when the lamp is energized, has delta chroma values for fifteen color samples of the color quality scale within select parameters. The delta chroma values are measured in the CIE LAB color space.