Light Source Device Retroreflective Lens Concealment

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Solution Overview

Problem

Existing light source devices that use a combination of light emitting diodes and phosphors struggle to reduce external light transmission while maintaining sufficient light emission, making it difficult to conceal the visibility of individual light emitting elements or phosphor layers.

Innovation Solution

A light source device design incorporating a light transmissive member with a retroreflective lens portion and a Fresnel lens portion, where the retroreflective lens portion faces the light emitting element and the Fresnel lens portion is positioned differently, reducing external light transmission while minimizing the decrease in emitted light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a light transmissive member is used to reduce external light transmission, then the concealing effect is improved, but the amount of light emitted from light emitting elements is greatly decreased

Engineering Contradiction:

Improveexternal light transmissionVSAvoidamount of light emitted

Core Design Contradiction:

Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The light transmissive member is divided into multiple regions with different functions: a first region with a retroreflective lens portion for light emission, and a second region with a different shape for reducing external light transmission. This segmentation allows each region to optimize its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the light transmissive member are given different optical properties: the first region has retroreflective characteristics to efficiently transmit light from the light emitting element, while the second region has a shape designed to block external light. This local differentiation resolves the contradiction by applying appropriate properties only where needed.

Inventive Principle:

Principle #3Local quality

2Illumination intensity

If a phosphor layer is disposed over light emitting elements to achieve white light, then color reproduction is improved, but the visibility of individual light emitting elements increases

Engineering Contradiction:

Improvecolor reproductionVSAvoidvisibility of light emitting elements

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The light transmissive member acts as an intermediary between the light emitting elements and the external environment. It allows the phosphor layer to be disposed over the light emitting elements for color conversion while simultaneously controlling light transmission to reduce visibility, thus mediating between color reproduction requirements and concealing requirements.

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

This design achieves a concealing effect by reducing the visibility of light emitting elements and phosphor layers while maintaining efficient optical characteristics and light emission.

Implementation Method 1

The light incident surface includes an inner region having a retroreflective lens portion

Methodology Applied

Scientific EffectRetroreflection: Retroreflector

Implementation Method 2

a light transmissive member having a light incident surface opposite to the light emitting element, and a light emitting surface

Methodology Applied

Scientific EffectLight transmission: Refraction

Data Source

PatentUS10608151B2Light source device

Publication Date: 2020.03.31 NICHIA CORP

AI summary

A light source device includes a light emitting element and a light transmissive member having a light incident surface opposite to the light emitting element, and a light emitting surface. The light incident surface includes an inner region having a retroreflective lens portion and directly facing the light emitting element, and an outer region having a shape different from a shape of the retroreflective lens.