Phosphor Light Pipe for Valley-Free Multi-Band Light Mixing

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Solution Overview

Problem

Existing light source apparatuses for medical equipment lack high color rendering properties due to low efficiency in combining color light beams from independent wavelength conversion devices, often resulting in wavelength distribution with valleys.

Innovation Solution

A light source apparatus that divides excitation light into multiple beams and uses a light pipe with phosphor layers on its inner surfaces to emit light beams with different wavelength bands, eliminating the need for wavelength selection elements and enhancing color rendering by combining light without valleys in the wavelength range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If independent wavelength conversion devices are used to generate color light beams, then the light source apparatus can produce multiple wavelength bands, but the combination efficiency is low and wavelength distribution has valleys

Engineering Contradiction:
Improvewavelength band coverageVSAvoidcombination efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent merges multiple wavelength conversion processes into a single integrated light pipe structure. Multiple phosphor layers (red, green, blue, near-infrared) are combined within one light guide, allowing excitation light to simultaneously generate multiple wavelength bands through a unified optical path, thereby improving combination efficiency and eliminating wavelength distribution valleys.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from a one-dimensional sequential arrangement of independent wavelength conversion devices to a multi-dimensional integrated structure where multiple phosphor layers are stacked within a single light pipe. This spatial reorganization allows parallel wavelength conversion processes to occur simultaneously within the same optical path, resolving the efficiency problem.

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

2Manufacturing precision

If wavelength selection elements are used to combine color light beams, then the wavelength distribution can be controlled, but the device complexity and cost increase

Engineering Contradiction:
Improvewavelength distribution controlVSAvoidcomponent count
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates wavelength selection elements (such as dichroic mirrors and beam combiners) from the optical system. Instead of using external wavelength selection devices to combine color light beams, the design relies on the inherent wavelength conversion properties of phosphor materials directly within the light pipe, thereby reducing device complexity and cost while maintaining wavelength distribution control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The light pipe structure performs wavelength conversion and light combination functions inherently through the phosphor layers, without requiring external wavelength selection elements. The system is self-sufficient in generating and combining multiple wavelength bands, eliminating the need for additional optical components and simplifying the overall device architecture.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If multiple independent wavelength conversion devices are used, then various wavelength bands can be generated, but the number of components and cost increase

Engineering Contradiction:
Improvewavelength band coverageVSAvoidcomponent count
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent combines multiple independent wavelength conversion devices into a single integrated light pipe containing multiple phosphor layers. This merging approach maintains the capability to generate various wavelength bands (red, green, blue, near-infrared) while significantly reducing the total component count by consolidating multiple functions into one structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The light pipe structure serves multiple functions simultaneously: it guides excitation light, hosts multiple phosphor layers for wavelength conversion, and combines all wavelength bands into a unified output. This multi-functional design eliminates the need for separate devices for each wavelength band, reducing component quantity while maintaining versatility.

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

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 apparatus achieves improved color rendering properties and allows for adjustable wavelength distribution, reducing component count and cost while providing uniform illuminance distribution.

Implementation Method 1

a light guide member including, on an inner side, a hollow light guide path having a first opening and a second opening on a side opposite to the first opening

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

the plurality of wavelength converters being configured to emit light beams having wavelength bands different from each other

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP4675162A1Light source device
Publication Date: 2026.01.07 SONY GROUP CORP
  • EP4675162A1 patent drawingFigure 1
  • EP4675162A1 patent drawingFigure 2~3
  • EP4675162A1 patent drawingFigure 4

AI summary

A light source apparatus according to one embodiment of the present disclosure includes: a light source unit that divides excitation light into a plurality of light beams and outputs the plurality of light beams; a light guide member including, on an inner side thereof, a hollow light guide path having a first opening and a second opening on a side opposite to the first opening, the light guide member having a plurality of wavelength converters provided on at least a portion of a side surface of the light guide path, the plurality of wavelength converters being configured to emit light beams having wavelength bands different from each other; and a light condenser device that guides each of the plurality of light beams output from the light source unit to a corresponding one of the plurality of wavelength converters.