Stacked Light Source Layout for Compact Color Adjustment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing light sources that adjust color of mixed-color light are large in size due to the configuration of multiple light-emitting regions and wavelength conversion layers.

Innovation Solution

A light-emitting element with stacked first and second light-emitting parts, each including semiconductor layers and light-emitting layers, combined with a wavelength conversion member having stacked phosphor layers excited by different lights, allowing for compact design and color adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple light-emitting regions and wavelength conversion layers are used to adjust color, then color adjustment capability is improved, but device size increases

Engineering Contradiction:
Improvecolor adjustment capabilityVSAvoiddevice size
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent transitions from a planar arrangement of multiple light-emitting regions to a vertical stacked configuration. Multiple light-emitting parts (first, second, third light-emitting parts) are arranged in the thickness direction rather than side-by-side, and wavelength conversion layers are stacked above corresponding light-emitting parts. This dimensional reorganization maintains color adjustment functionality while significantly reducing the lateral area occupied by the device.

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

Solution Approach 2:

The patent implements a nested structure where wavelength conversion layers are positioned directly above their corresponding light-emitting parts, with subsequent light-emitting parts stacked above previous ones. Each layer is contained within the vertical projection of the layers below it, creating a compact nested arrangement that reduces overall device footprint while maintaining all functional components.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If multiple light-emitting regions are arranged in planar configuration, then color adjustment is enabled, but light extraction efficiency decreases

Engineering Contradiction:
Improvecolor adjustmentVSAvoidlight extraction efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent moves from a two-dimensional planar arrangement to a three-dimensional vertical stacking configuration. Light-emitting parts are arranged in the thickness direction with wavelength conversion layers positioned above them, allowing light to extract upward through the wavelength conversion layers rather than laterally through adjacent regions. This improves light extraction efficiency by providing dedicated extraction paths for each wavelength component.

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

3Area of stationary object

If stacked light-emitting parts and phosphor layers are used, then device size is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvedevice sizeVSAvoidstacked structure complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent divides the light source into discrete, modular segments: first light-emitting part with its wavelength conversion layer, second light-emitting part with its wavelength conversion layer, and third light-emitting part. Each segment can be independently fabricated and then stacked in sequence, simplifying the manufacturing process compared to creating a monolithic complex structure. The segmentation allows for standardized production of individual layers that are then assembled through stacking.

Inventive Principle:
Principle #1Segmentation

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 solution reduces the size of the light source while enabling efficient color adjustment of mixed-color light, expanding the color temperature and chromaticity range, and improving light extraction efficiency.

Implementation Method 1

a first phosphor layer configured to be excited by the first light and emit third light

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

a second phosphor layer configured to be excited by the second light and emit fourth light

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP4626188A1Light source, light-emitting module, and mobile terminal
Publication Date: 2025.10.01 NICHIA CORP
  • EP4626188A1 patent drawingFigure 1
  • EP4626188A1 patent drawingFigure 2
  • EP4626188A1 patent drawingFigure 3A

AI summary

A light source includes: a light-emitting element including: a first light-emitting part configured to emit first light, and a second light-emitting part configured to emit second light having a peak emission wavelength different from a peak emission wavelength of the first light, wherein: the first light-emitting part and the second light-emitting part are stacked in a first direction; and a wavelength conversion member disposed on the light-emitting element, the wavelength conversion member including: a first phosphor layer configured to be excited by the first light and emit third light, and a second phosphor layer configured to be excited by the second light and emit fourth light having a peak emission wavelength different from a peak emission wavelength of the third light, wherein: the first phosphor layer and the second phosphor layer are stacked in the first direction.