Light-emitting Device Package with Phosphor Spectrum Control

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Solution Overview

Problem

Existing light-emitting device packages fail to minimize harmful wavelength ranges and maximize beneficial wavelength ranges for human health, while also enhancing luminous flux and improving the R9 CRI index.

Innovation Solution

A light-emitting device package is designed with a body made from high reflectivity materials, incorporating specific phosphors with peak wavelengths of 535 nm for green light and 610 nm for red light, which control the emission spectrum to prioritize the beneficial 465 nm to 495 nm wavelength range and improve the R9 CRI index by using a combination of phosphors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a blue LED with center wavelength of 440 nm to 450 nm is used to increase energy efficiency, then energy efficiency is improved, but harmful wavelength range (415 nm to 455 nm) is increased causing eye hazards

Engineering Contradiction:
Improveenergy efficiencyVSAvoideye hazard
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the harmful wavelength component (415-455 nm) from the blue LED spectrum by using a bandpass filter that transmits only the beneficial wavelength range (465-495 nm), thereby eliminating eye hazards while preserving energy efficiency

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A bandpass filter is introduced as an intermediary component between the blue LED and the phosphors, selectively transmitting only the beneficial wavelength range (465-495 nm) while blocking harmful wavelengths, thus mediating between energy efficiency and eye safety

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If filters are used to decrease hazardousness in wavelength range 415 nm to 455 nm, then eye safety is improved, but blue range necessary for manufacturing white light source and wavelength range 465 nm to 495 nm beneficial for circadian rhythm control is removed

Engineering Contradiction:
Improveeye safetyVSAvoidluminous flux
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

A bandpass filter with specific transmission characteristics (465-495 nm) is used as an intermediary that selectively passes only the beneficial wavelength range while blocking harmful wavelengths, thereby achieving eye safety without removing the blue range needed for white light production and circadian rhythm regulation

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If phosphors with long photoluminescence wavelength are used, then R9 CRI index is improved, but light efficiency is lower than phosphors having short wavelength

Engineering Contradiction:
ImproveR9 CRI indexVSAvoidlight efficiency
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent optimizes the photoluminescence wavelength parameter of the red phosphor to a specific range (610-650 nm) that achieves both improved R9 CRI index (greater than 0) and acceptable light efficiency, balancing between color rendering quality and energy loss

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 solution effectively reduces the harmful 415 nm to 455 nm wavelength range and increases the beneficial 465 nm to 495 nm range, enhancing luminous flux and improving the R9 CRI index from -11.9 to 2.7, providing a lighting device that is safer for human health and more efficient.

Implementation Method 1

incorporating specific phosphors with peak wavelengths of 535 nm for green light and 610 nm for red light, which control the emission spectrum

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

A light-emitting device package is designed with a body made from high reflectivity materials

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3364470B1Light-emitting device package and lighting device
Publication Date: 2021.06.30 SUZHOU LEKIN SEMICON CO LTD
  • EP3364470B1 patent drawingFigure 1a
  • EP3364470B1 patent drawingFigure 1b~2
  • EP3364470B1 patent drawingFigure 3~4

AI summary

An embodiment relates a light-emitting device package and a lighting device. A light-emitting device package according to an embodiment may include a package body 11, a light-emitting device 25 disposed on the package body 11, a molding member 41 disposed on the light-emitting device 25, and a phosphor 30 disposed in the molding member 41. An energy ratio of a first wavelength range of 415 nm to 455 nm of the light-emitting device may be 75% or less of energy of a sunlight source having the first wavelength range. An energy ratio of a second wavelength range of 465 nm to 495 nm of the light-emitting device may be 60% or more of energy of a sunlight source having the second wavelength range. Moreover, the energy ratio of the second wavelength range of 465 nm to 495 nm may be higher than the energy ratio of a first wavelength range of 415 nm to 455 nm in the light-emitting device. The phosphor 30 may include a first phosphor 31 which is a green phosphor and a second phosphor 32 which is a red phosphor, thereby implementing a white light source with an emission wavelength of the light-emitting device 25 as an excitation wavelength.