Reflective Laser Illuminator with Sparse Phosphor Intensity

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Solution Overview

Problem

Conventional illuminating devices using solid-state light sources face challenges in increasing output while inhibiting the increase in temperature of the phosphor layer, as diffusion techniques lead to light scattering and loss.

Innovation Solution

An illuminating device of a reflective type that uses a laser beam, featuring a laser element, optical fibers, and an optical component that causes reflected laser beams to be incident on the phosphor layer in a sparse intensity distribution, preventing central condensation and thus maintaining low temperature and high output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a diffusion member is used to diffuse light emitted by a solid-state light source, then the temperature increase of the phosphor layer is inhibited, but light is scattered and lost, making it difficult to increase the output of the illuminating device

Engineering Contradiction:
Improvetemperature of phosphor layerVSAvoidoutput of illuminating device
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The invention divides the illumination area into multiple segments by using multiple laser elements arranged in an array, with each element having its own optical fiber and reflection optical member. This segmentation allows independent control of light intensity distribution across different regions, enabling the central region to receive less light (reducing temperature) while peripheral regions provide the main illumination output.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies different optical characteristics to different regions: the central region has reduced light intensity (sparse intensity distribution) to prevent overheating, while the peripheral regions have higher light intensity to maintain overall output. Each reflection optical member is specifically designed to direct light to its corresponding region, creating localized quality differences that resolve the temperature-output contradiction.

Inventive Principle:
Principle #3Local quality

2Use of energy by moving object

If blue light is directly irradiated onto the phosphor layer using a solid-state light source, then the energy density is high, but the phosphor generates a large amount of heat in the irradiated region, causing temperature increase and reduced wavelength conversion efficiency

Engineering Contradiction:
Improveenergy density of blue lightVSAvoidtemperature of phosphor layer
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The invention changes the spatial distribution parameter of light intensity by using reflection optical members to create a sparse intensity distribution pattern. Instead of uniform high energy density across the phosphor layer, the system distributes energy sparsely in the central region and more densely in peripheral regions, maintaining overall energy utilization while preventing localized overheating that would reduce conversion efficiency.

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 device effectively increases output while preventing phosphor layer temperature increase, ensuring efficient light conversion and reduced degradation, with a sparse intensity distribution at the central region of the phosphor layer.

Implementation Method 1

an optical fiber that transmits the laser beam emitted by the laser element

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

a phosphor layer that converts a wavelength of light incident on one of surfaces and emits the light through the one of the surfaces

Methodology Applied
Scientific EffectWavelength conversion: Photoluminescence

Implementation Method 3

an optical component that causes reflected light of the laser beam transmitted through the optical fiber to be incident on the one of the surfaces of the phosphor layer

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3916289B1Illuminating device
Publication Date: 2024.07.03 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3916289B1 patent drawingFigure 1
  • EP3916289B1 patent drawingFigure 2
  • EP3916289B1 patent drawingFigure 3

AI summary

An illuminating device (1) according to the present disclosure is of a reflective type and uses a laser beam. The illuminating device (1) includes: a laser element (83) that emits a laser beam; an optical fiber (11) that transmits the laser beam emitted by the laser element (83); a phosphor layer (40) that converts a wavelength of light incident on one of surfaces and emits the light through the one of the surfaces; and an optical component (60) that causes reflected light of the laser beam transmitted through the optical fiber (11) to be incident on the one of the surfaces of the phosphor layer (40). With the illuminating device (1), an intensity distribution of the light incident on the one of the surfaces of the phosphor layer (40) is sparse at a central region.