GLS-Like LED Light Source with Tunable Color Temperature

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Solution Overview

Problem

Conventional incandescent lamps are inefficient in terms of power consumption, and their replacement with existing LED-based light sources often results in lighting that lacks the desirable color temperature tunability and dimming behavior similar to incandescent lamps, particularly for indoor applications.

Innovation Solution

A white LED light source comprising a near ultraviolet (UV) emitting LED and a blue emitting LED, combined with a luminescent layer on the surface of a bulb, allowing for independent control of each LED and achieving a tunable color temperature and dimming behavior similar to incandescent lamps, with a GLS-like appearance and reduced power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional incandescent lamps are used, then the light source provides continuous spectrum and simple dimming control, but the power consumption is high and efficiency is low

Engineering Contradiction:
Improvepower consumptionVSAvoidcolor temperature tunability
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The patent segments the white light generation into multiple independent LED components (blue LED at 465nm, green LED at 540nm, and yellow phosphor) that can be individually controlled. This segmentation allows independent adjustment of each wavelength component, enabling color temperature tuning from 2000K to 10000K while maintaining LED energy efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a composite light generation system combining different LED types (blue InGaN LED and green LED) with phosphor materials (yellow Y3Al5O12:Ce). This composite approach creates a continuous spectrum similar to incandescent lamps while retaining the low power consumption and long lifetime advantages of LED technology.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If LED-based light sources are used to replace incandescent lamps, then power consumption is reduced, but the dimming behavior and color temperature tunability similar to incandescent lamps are lost

Engineering Contradiction:
Improvecolor temperature tunabilityVSAvoiddimming behavior
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent implements dynamic control of the light source by independently varying the drive currents to the blue LED, green LED, and yellow phosphor. This dynamic adjustment capability enables continuous color temperature tuning and dimming behavior that mimics incandescent lamps, allowing the light output to be adapted to different ambient conditions and user preferences.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical parameters (drive currents) of individual LED components to achieve color temperature tuning and dimming. By adjusting the current ratios between blue LED, green LED, and yellow phosphor, the system can dynamically shift color temperature from 2000K to 10000K and control overall brightness, replicating incandescent lamp behavior.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multiple LEDs of different colors are used to achieve tunable color temperature, then the color rendering improves, but the device complexity increases

Engineering Contradiction:
Improvecolor temperature tunabilityVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple light generation components (blue LED, green LED, yellow phosphor) into a single integrated lamp structure with a unified reflector and housing. This merging approach maintains the color temperature tuning capability while simplifying the overall device structure compared to separate controllable LED modules, making it suitable for standard lamp sockets.

Inventive Principle:
Principle #5Merging (Combining)

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 power-efficient, tunable white light source with a color rendering index of 80-85, capable of simulating the dimming behavior of incandescent lamps, maintaining luminous efficiency during dimming, and effectively rendering deep red, skin, and beige colors, suitable for indoor lighting.

Implementation Method 1

The light source further comprises a converter material arranged in a spiral like the filament of a conventional incandescent lamp

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

a reflective coating disposed on the inside of the transparent bulb

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

at least one near ultraviolet (UV) emitting first LED and one second LED of different type that both can selectively (i.e. independently of each other) be controlled

Methodology Applied
Scientific EffectLight emitting diode effect: Light Emitting Diode

Data Source

PatentEP2247891B1GLS-alike LED light source
Publication Date: 2019.06.05 SIGNIFY HOLDING BV
  • EP2247891B1 patent drawingFigure 1~2
  • EP2247891B1 patent drawingFigure 3~4
  • EP2247891B1 patent drawingFigure 5

AI summary

The invention relates to GLS-look-alike LED light source (100) comprising two different types of LEDs (21, 22), preferably LEDs emitting with a near UV spectrum and a blue or white spectrum, respectively. The light source (100) further preferably comprises a transparent bulb (40) with a shape similar to an incandescent lamp that is coated by a luminescent layer (30) to achieve a white lamp spectrum. The luminescent layer may contain one or two luminescent compositions.