Lighting Device with Mixed White and Full-Color LED Reflection

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Solution Overview

Problem

Conventional white LED lighting devices have low color rendering properties and vividness due to biased spectral distribution, particularly lacking in red light components.

Innovation Solution

A lighting device incorporating a white light source and a full-color light source, with a control unit that mixes reflected light from both sources using a reflecting portion to enhance color rendering, where the full-color light source is activated to compensate for the lack of red light in the white light source's emission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a white LED is used as the light source, then energy efficiency is improved, but color rendering property deteriorates due to biased spectral distribution

Engineering Contradiction:
Improveenergy efficiencyVSAvoidcolor rendering property
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent combines a white LED and a full-color LED into a single lighting device, merging their light outputs through a common reflecting portion. The white LED provides energy-efficient illumination while the full-color LED supplements the spectral distribution, particularly adding red light components. Their reflected lights are mixed to achieve both energy efficiency and improved color rendering property.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a composite light source system where two different LED types (white LED and full-color LED) work together. This composite approach allows the system to leverage the energy efficiency of white LEDs while simultaneously incorporating the full spectral output of full-color LEDs, resulting in a lighting solution that achieves both energy efficiency and high color rendering property.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If a white LED with blue LED and yellow phosphor is used, then manufacturing simplicity is improved, but spectral distribution balance deteriorates with low red light component

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidspectral distribution balance
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent merges the simple white LED structure with a full-color LED to compensate for spectral imbalance. The white LED maintains manufacturing simplicity while the added full-color LED provides the missing red light component, achieving spectral balance without complicating the base manufacturing process.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent applies local quality enhancement by adding the full-color LED specifically to supplement the red light component where it is deficient. The full-color LED is positioned and controlled to target the spectral gap in the white LED output, particularly enhancing red light emission while maintaining the overall simplicity of the white LED structure.

Inventive Principle:
Principle #3Local quality

3Device complexity

If only a white light source is used, then device complexity is reduced, but color rendering property and vividness deteriorate

Engineering Contradiction:
Improvedevice complexityVSAvoidcolor rendering property
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent combines a white light source and a full-color light source in a unified lighting device with a shared reflecting portion. This merging approach enhances color rendering property by combining the outputs of two light sources, achieving high color rendering without significantly increasing overall device complexity through shared structural elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The reflecting portion serves multiple functions: it reflects light from both the white LED and the full-color LED, and it provides a common path for mixing their outputs. This multi-functionality reduces the need for separate optical components for each LED type, thereby maintaining relatively low device complexity while achieving improved color rendering property.

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

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 achieves an even spectral distribution and enhanced color rendering properties, mimicking natural light, by mixing the light from white and full-color LEDs, thereby improving the illumination's vividness and color accuracy.

Implementation Method 1

a reflecting portion that reflects light from the white light source and the full-color light source

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3873179B1Lighting device
Publication Date: 2022.07.13 YAZAKI CORP
  • EP3873179B1 patent drawingFigure 1
  • EP3873179B1 patent drawingFigure 2
  • EP3873179B1 patent drawingFigure 3

AI summary

A lighting device includes a white LED, a full-color LED, and a reflecting portion. The reflecting portion reflects light from the white LED and the full-color LED. A microcomputer turns on the full-color LED to emit light containing a red light component while the white LED is on. Further, the white LED and the full-color LED are arranged so that reflected lights thereof reflected by the reflecting portion are mixed to perform illumination. Thereby, direct lights of the white LED and the full-color LED cannot be visually recognized. Further, light from the white LED with a lot of blue components is compensated with light containing a red component from the full-color LED, and spectral distribution can be made even and illumination close to that of natural light can be performed.