Fluorescent Member Inclination for Light Projection Efficiency

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Solution Overview

Problem

Conventional light projection apparatuses with fluorescent members suffer from inefficient light use due to uncontrollable light output, where part of the light exits without being reflected, reducing the ability to effectively illuminate desired regions.

Innovation Solution

A light projection unit with a fluorescent member that inclines its illuminated surface opposite to the projection direction, combined with a reflection member that reflects most of the fluorescent light, ensuring that about 90% or more of the light is output from the illuminated surface and efficiently directed, utilizing a Lambertian light intensity distribution and a parabolic or elliptic reflection surface to collimate the light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the fluorescent member outputs light in all directions (conventional design), then the light output is omnidirectional, but the light use efficiency decreases because part of the light exits without being reflected by the reflection member

Engineering Contradiction:

Improvelight use efficiencyVSAvoidlight direction control

Core Design Contradiction:

Loss of energyVSEase of operation

Solution Approach 1:

The illuminated surface of the fluorescent member is inclined at a specific angle (e.g., 45 degrees) relative to the optical axis, creating an asymmetric light output pattern. This asymmetry directs the majority of the fluorescent light toward the reflection member while minimizing direct exit, thereby improving light use efficiency without requiring complex additional components

Inventive Principle:

Principle #4Asymmetry

2Loss of energy

If the illuminated surface is inclined opposite to the projection direction, then most light is directed toward the reflection member, but the structural configuration becomes more complex

Engineering Contradiction:

Improvelight use efficiencyVSAvoidstructural complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The fluorescent member is integrated directly with the reflection member in a compact arrangement where the inclined illuminated surface of the fluorescent member directly interfaces with the reflection member. This merging eliminates the need for separate light guiding components and simplifies the overall structure while maintaining high light use efficiency

Inventive Principle:

Principle #5Merging (Combining)

3Manufacturing precision

If a parabolic or elliptic reflection surface is used to collimate light, then the illumination precision improves, but the manufacturing complexity increases

Engineering Contradiction:

Improveillumination precisionVSAvoidmanufacturing ease

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Instead of requiring a perfectly formed parabolic or elliptic reflection surface, the design uses a reflection member with simplified geometry that reflects light over a sufficient angular range to achieve adequate collimation. This partial action approach provides acceptable illumination precision while significantly reducing manufacturing complexity and cost

Inventive Principle:

Principle #16Partial or excessive action

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 significantly improves light use efficiency by directing most of the fluorescent light towards the desired region, reducing glare and enhancing illumination, while also efficiently radiating heat to prevent the fluorescent member from overheating.

Implementation Method 1

a fluorescent member that includes an illuminated surface to which laser light is directed, converts at least part of the laser light into fluorescent light and outputs the fluorescent light

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Implementation Method 2

a reflection member that includes a first reflection surface which is disposed to oppose the illuminated surface of the fluorescent member and reflects the fluorescent light output from the fluorescent member

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentEP2518560B1Light projection unit and light projection apparatus comprising a fluorescent member.

Publication Date: 2017.05.31 SHARP KK

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AI summary

A light projection unit capable of improving light use efficiency is provided. This light projection unit includes: a fluorescent member that includes an illuminated surface to which laser light is directed, converts at least part of the laser light into fluorescent light and outputs the fluorescent light from chiefly the illuminated surface; and a reflection member that includes a first reflection surface which reflects the fluorescent light output from the fluorescent member. The illuminated surface of the fluorescent member is inclined with respect to a predetermined direction in such a way that the illuminated surface faces in a direction opposite to a light projection direction.