Light-emitting Device Color Temperature Adjustment via Current Distribution

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Solution Overview

Problem

Existing light-emitting devices with multiple color temperatures require complex switching circuits and control systems, increasing costs and complexity.

Innovation Solution

A light-emitting device with three or more wires connected to different light-emitting portions, each containing red and green phosphors and an LED element, allowing for adjustable color temperature using a single power source by varying the current distribution across the wires.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple light-emitting portions with different color temperatures are used, then color temperature adjustment capability is improved, but device complexity increases due to requiring switching circuits and control circuits

Engineering Contradiction:
Improvecolor temperature adjustment capabilityVSAvoidcircuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple light-emitting portions (first, second, and third light-emitting portions with different color temperatures) into a single integrated device structure. By merging these portions and connecting them in parallel to a single power source without requiring external switching circuits, the device achieves color temperature adjustment capability while reducing overall circuit complexity. The integration allows direct current control to adjust the contribution of each light-emitting portion to the total light output.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single power source in the patent serves multiple functions simultaneously: it powers all three light-emitting portions with different color temperatures and enables color temperature adjustment through current control. This multi-functional approach eliminates the need for separate switching circuits and control circuits, reducing device complexity while maintaining adaptability for color temperature adjustment.

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

2Illumination intensity

If halogen lamp is used for color temperature adjustment, then color rendering properties are improved, but power consumption increases and operating time decreases

Engineering Contradiction:
Improvecolor rendering propertiesVSAvoidpower consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent uses LED light-emitting portions with different color temperatures (different spectral characteristics) instead of halogen lamps. By changing the parameter of light source type from thermal radiation (halogen) to electroluminescence (LED), the device achieves comparable color rendering properties while dramatically reducing power consumption. The current control mechanism allows adjustment of the effective color temperature by varying the relative contribution of each LED portion.

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

Enables adjustable color temperature with reduced complexity and cost by using a single power source, improving light emission efficiency and longevity.

Implementation Method 1

each of the first light-emitting portion, the second light-emitting portion, and the third light-emitting portion includes a first red phosphor, a second red phosphor, a green phosphor and an LED element connected in series

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 2

the phosphor being dispersed in the transparent resin, each of the first light-emitting portion, the second light-emitting portion, and the third light-emitting portion being sealed with the transparent resin in which the phosphor is dispersed

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP3270429B1Light-emitting device
Publication Date: 2020.03.04 SHARP KK
  • EP3270429B1 patent drawingFigure 1
  • EP3270429B1 patent drawingFigure 2
  • EP3270429B1 patent drawingFigure 3

AI summary

Provided is a light-emitting device that is able to adjust a color temperature by power supplied from a single power source. The light-emitting device includes an anode electrode land, a cathode electrode land, and three or more wires that are provided in parallel and are connected to the anode electrode land and the cathode electrode land, in which at least three wires among the three or more wires have different forward current-forward voltage characteristics and are connected to different light emitting portions, and the color temperature of light emitted from the whole of the light-emitting portions is able to be adjusted.