Composite Microscope Light Source Layout for Stable UV Output

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Solution Overview

Problem

Fluorescence microscope light source devices using laser-excited light sources suffer from low light output efficiency and significant heat generation, which affects the performance of LEDs, particularly those emitting UV light, leading to reduced UV output due to increased temperature.

Innovation Solution

A light source device incorporating a semiconductor laser for excitation, a phosphor, and multiple LEDs with different wavelengths, where the UV-LED is positioned farther from the laser-excited light source to minimize heat impact, combined with a composite optical system using dichroic mirrors for efficient light synthesis and emission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a laser-excited light source is used to obtain fluorescence with a spectrum corresponding to many fluorescent reagents, then the illumination intensity and spectral coverage are improved, but the heat generation increases significantly, causing temperature rise in nearby LEDs

Engineering Contradiction:
Improvelight outputVSAvoidtemperature of LED
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent transitions from a linear arrangement where LEDs are positioned close to the laser light source to a spatially distributed arrangement. By placing LEDs at different distances from the heat source along the optical path, the system creates thermal zones with different temperature characteristics, allowing UV-LEDs to be positioned in cooler regions while other LEDs operate in warmer zones.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Different LEDs are assigned to different positions along the optical path based on their thermal sensitivity. UV-LEDs, which are highly sensitive to temperature, are placed farther from the laser light source where temperatures are lower, while other LEDs can tolerate higher temperatures closer to the heat source. This local optimization ensures each LED operates in its optimal temperature range.

Inventive Principle:
Principle #3Local quality

2Volume of moving object

If the light source device is made compact to reduce size, then the volume is reduced, but the arrangement interval between components becomes small, causing LEDs to be exposed to higher temperatures

Engineering Contradiction:
Improvedevice sizeVSAvoidtemperature of LED
Core Design Contradiction:
Volume of moving objectVSTemperature

Solution Approach 1:

Instead of arranging components in a compact planar configuration, the patent utilizes the optical path dimension (depth) to distribute LEDs at different distances from the heat source. This three-dimensional arrangement allows adequate thermal spacing while maintaining a compact overall device volume, as the heat dissipation gradient extends along the optical axis rather than requiring lateral separation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If UV-LEDs are positioned close to the laser-excited light source for compact arrangement, then the device complexity is reduced, but the UV light output decreases due to temperature rise

Engineering Contradiction:
Improvearrangement complexityVSAvoidUV light output
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The patent applies local quality optimization by positioning UV-LEDs in a specific region (farther from the heat source) where temperature conditions are suitable for maintaining high UV light output. This localized placement strategy preserves UV performance without requiring complex active cooling systems or sophisticated thermal management, achieving a balance between simplicity and performance.

Inventive Principle:
Principle #3Local quality

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

This configuration stabilizes UV light output, reduces temperature-related losses, and allows for a compact design by effectively managing heat dissipation and light alignment, ensuring consistent radiation intensity.

Implementation Method 1

at least one semiconductor laser for excitation and a laser-excited light source. The laser-excited light source has a phosphor excited by the semiconductor laser(s)

Methodology Applied
Scientific EffectLight emission from semiconductor laser: Light

Implementation Method 2

a phosphor excited by the semiconductor laser(s), and an optical system (first optical system) for extracting fluorescence emitted from the phosphor

Methodology Applied
Scientific EffectPhosphorescence: Phosphorescence

Implementation Method 3

using dichroic mirrors (DM) to combine light from the phosphor, which is excited by the semiconductor laser, with the emitted light from two LEDs having different wavelengths

Methodology Applied
Scientific EffectDichroic reflection: Dichroic Filter

Implementation Method 4

a composite optical system (second optical system) for synthesizing (combining) the fluorescence from the laser-excited light source with the light from the LED light sources

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3799228B1Light source device
Publication Date: 2023.12.13 USHIO INC
  • EP3799228B1 patent drawingFigure 1
  • EP3799228B1 patent drawingFigure 2
  • EP3799228B1 patent drawingFigure 3

AI summary

A light source device (100) includes at least one semiconductor laser (103) and a laser-excited light source (110). The laser-excited light source (110) has a phosphor (104) excited by the semiconductor laser(s), and an optical system (105) for extracting fluorescence emitted from the phosphor. The light source device also includes a plurality of LED light sources (120A, 120B, 120C, 120D) for emitting light having wavelengths different from a wavelength of the fluorescence. The light source device also includes a composite optical system (130) for synthesizing the fluorescence from the laser-excited light source with the light from the LED light sources, and emitting the synthesized light from a light emitting portion (102). The LED light sources include an LED light source (120A) configured to emit light in an ultraviolet range. The LED light source (120A) configured to emit the light in the ultraviolet range is disposed at a position farther from the laser-excited light source than the remaining LED light source(s) (120B-120D).