Laser SMD Phosphor Package With Reflective Light Incoupling

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Solution Overview

Problem

Existing light sources, particularly laser-phosphor systems, face challenges with heat management and achieving compact, high-power devices while maintaining efficiency and brightness.

Innovation Solution

A light generating system comprising a lighting unit, a luminescent element, an optical element, and a reflective element, where the luminescent element converts unit light into luminescent material light, and the optical element and reflective element aid in thermal management and light distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional LEDs are used with phosphor down-conversion, then yellow light is generated but the blue portion of the spectrum is lost and color rendering is poor

Engineering Contradiction:
Improvecolor renderingVSAvoidblue spectrum loss
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent segments the light generation process into multiple independent laser sources (blue laser at 450nm and green laser at 530nm) instead of using a single LED with phosphor. This segmentation allows each laser to emit at specific wavelengths without spectral overlap losses, thereby preserving the blue portion of the spectrum while achieving full-color output with superior color rendering.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the fundamental parameter of light generation from LED electroluminescence with phosphor down-conversion to direct laser emission. By using lasers with narrow spectral linewidths and specific wavelengths (450nm blue and 530nm green), the system achieves precise spectral control that eliminates the inherent spectral loss of phosphor-based conversion while maintaining high brightness.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If multiple separate laser modules are combined to achieve full color, then color rendering improves but device complexity and alignment precision requirements increase

Engineering Contradiction:
Improvefull color outputVSAvoidmodule integration
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent merges multiple laser sources (blue and green lasers) and the phosphor layer into a single integrated laser module package. The lasers are mounted on a common substrate with the phosphor layer positioned above, creating a compact unified structure that simplifies integration compared to combining separate laser modules. This merging reduces alignment complexity while maintaining full-color output capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The laser module is designed with universal functionality to generate multiple colors (blue, green, and yellow-green) within a single device. The blue laser directly emits blue light, the green laser emits green light that excites the phosphor to produce yellow-green light, and these combine to create full-color output. This multi-functional design eliminates the need for separate modules for different color ranges.

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

3Device complexity

If phosphor is placed directly over the laser source, then structure is simplified but heat management becomes difficult and phosphor degradation accelerates

Engineering Contradiction:
ImprovestructureVSAvoidphosphor stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces an intermediary reflective layer (silver or aluminum) between the laser source and the phosphor layer. This reflective layer serves multiple functions: it directs laser light upward onto the phosphor for efficient conversion, it protects the phosphor from direct exposure to the high-power laser beam that would cause degradation, and it facilitates heat management by reflecting thermal radiation. This intermediary structure maintains simplicity while enhancing reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If LED with phosphor is used, then manufacturing is simple but spectral efficiency is poor and color accuracy is limited

Engineering Contradiction:
Improvemanufacturing processVSAvoidspectral control
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the light generation mechanism from broad-spectrum LED emission with phosphor down-conversion to narrow-line laser emission. Lasers provide precise wavelength control (450nm blue, 530nm green) with minimal spectral bandwidth, enabling accurate color rendering and spectral efficiency. This parameter change from broadband to narrowband emission maintains manufacturing simplicity while dramatically improving spectral control precision.

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 system enables easier thermal management by distributing light over the surface of the luminescent element and dissipating heat through the optical element to a thermally conductive element, while allowing for high intensities and compact designs.

Implementation Method 1

blauwer Laser (450 nm), der den Phosphor zum Koppeln mit dem grünen Laser (530 nm) anregt

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

grünen Laser (530 nm)

Methodology Applied
Scientific EffectLaser emission: Laser

Data Source

PatentEP4256387B1Laser SMD package with phosphor and light incoupler
Publication Date: 2025.05.07 SIGNIFY HOLDING BV
  • EP4256387B1 patent drawingFigure 1A
  • EP4256387B1 patent drawingFigure 1B(I)~1B(III)
  • EP4256387B1 patent drawingFigure 1C

AI summary

:The invention provides a light generating system (1000) comprising a lighting unit (100), a luminescent element (210), an optical element (400), and a reflective element (510), wherein: (a) the lighting unit (100) is configured to generate a beam (102) of unit light (101); (b) the luminescent element (210) comprises a luminescent material (200) configured to convert at least part of the unit light (101) into luminescent material light (201); wherein the luminescent element (210) comprises a first luminescent element face (211) and a second luminescent element face (212), wherein at least part of the luminescent material (200) is configured between the first luminescent element face (211) and the second luminescent element face (212); (c) the optical element (400) comprises an external surface (410), wherein the optical element (400) is configured between the luminescent element (210) and 10the reflective element (510), wherein a first part (421) of the external surface (410) is directed to the second luminescent face (212), wherein a second part (422) of the external surface (410) is directed to the reflective element (510), and wherein a third part (423) of the externa surface (410) is configured in a light receiving relationship with the lighting unit (100); wherein a first area A1 of the first part (421) is smaller than a second area A2 of the second part (422), wherein the optical element (400) is transmissive for the unit light (101); (d) the reflective element (510) is configured to reflect unit light (101); and (e) the lighting unit (100) is configured such that in an operational mode the lighting unit (100) is configured to irradiate the first element face (211) via transmission through the optical element (400) and reflection at the reflective element (510).