Light Source Device Wavelength Conversion Layer Efficiency

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Solution Overview

Problem

Conventional light source devices using solid light-emitting devices struggle to achieve high efficiency in converting excited light into desired wavelengths due to thin wavelength conversion layers and degradation issues with transparent resins under heat and light exposure.

Innovation Solution

A light source device incorporating a wavelength conversion member with a light transmission plate, a wavelength conversion layer, a light reflection member, and a filter member, where the excited light is incident at an angle and the wavelength conversion layer is formed using a sol-gel or deposition process to enhance efficiency and prevent light leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the wavelength conversion layer is formed by methods (1) to (3) to achieve thin layer formation, then the manufacturing process is simple, but the conversion efficiency is insufficient due to light penetration

Engineering Contradiction:
Improvewavelength conversion layer formation processVSAvoidlight conversion efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent changes the thickness parameter of the wavelength conversion layer from thin (conventional) to thick (5-20 μm), fundamentally altering the light interaction mechanism to achieve high conversion efficiency while maintaining manufacturing simplicity through the sol-gel process

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials consisting of fluorescent particles dispersed in a transparent resin matrix, creating a wavelength conversion layer that combines the light-absorbing properties of fluorescent materials with the optical transparency of the resin, enabling both thick layer formation and high conversion efficiency

Inventive Principle:
Principle #40Composite materials

2Productivity

If the wavelength conversion layer is formed by method (4) to achieve large thickness, then the light conversion efficiency is improved, but the transparent resin is easily decomposed or deteriorated by excited light or heat

Engineering Contradiction:
Improvelight conversion efficiencyVSAvoidtransparent resin stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent optimizes the thickness parameter to a specific range (5-20 μm) that is thick enough to ensure high light conversion efficiency but thin enough to prevent excessive heat accumulation and resin degradation, achieving a balance between productivity and reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by using transparent resin only as a matrix to hold fluorescent particles, rather than as the primary wavelength conversion material. The fluorescent particles perform the actual conversion while the resin provides structural support, localizing the stress and heat resistance requirements to specific functional zones

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If three kinds of solid light-emitting devices are used to emit red, green and blue light, then the desired wavelengths can be obtained, but the device cost increases and the life cycle decreases

Engineering Contradiction:
Improvewavelength emission capabilityVSAvoidnumber of light-emitting devices
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the single excited light source universal by using a wavelength conversion layer that can convert the excited light into multiple wavelengths (red, green, and blue) simultaneously. This multi-functional approach eliminates the need for three separate light-emitting devices while maintaining full color emission capability

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces the wavelength conversion layer as an intermediary between the excited light source and the final light output. This intermediary converts the single wavelength excited light into multiple wavelengths, serving as a mediator that enables full-color emission without requiring multiple light sources

Inventive Principle:
Principle #24Intermediary (Mediator)

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 device efficiently converts excited light into long-wavelength light, achieving high luminance efficiency by reflecting and re-incidence of excited light within the wavelength conversion layer, thereby improving light emission quality.

Implementation Method 1

a wavelength conversion layer made of a fluorescent material converting excited light into visible light

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

a light reflection member provided at one side of the wavelength conversion member and including an excited light transmission window transmitting the excited light

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

a filter member provided at the other side of the wavelength conversion member and reflecting the excited light and transmitting the long-wavelength light

Methodology Applied
Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentEP2602537B1Light source device
Publication Date: 2018.02.28 USHIO INC
  • EP2602537B1 patent drawingFigure 1~2
  • EP2602537B1 patent drawingFigure 3(a)~4
  • EP2602537B1 patent drawingFigure 5(a)~6

AI summary

Provided is a light source device for converting excited light into long-wavelength light having a longer wavelength than the excited light to more efficiently emit the light having a desired wavelength. The light source includes: an excited light source emitting excited light; a wavelength conversion member including a light transmission plate and a wavelength conversion layer formed on the light transmission plate and receiving the excited light from the excited light source and emitting long-wavelength light having a longer wavelength than the excited light, the excited light emitted from the excited light source being incident upon one side of the wavelength conversion layer; a light reflection member provided at one side of the wavelength conversion member and including an excited light transmission window transmitting the excited light; and a filter member provided at the other side of the wavelength conversion member and reflecting the excited light and transmitting the long-wavelength light.