Light Emitting Device Color Temperature Adjustment

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Solution Overview

Problem

Existing light emitting devices require complex wiring patterns and structures due to the need for separate power sources for different light-emitting elements, leading to issues with mixed light color uniformity and temperature characteristics, especially when using LEDs of different luminescent colors.

Innovation Solution

A light-emitting device with a reflector housing that uses a single power source to connect first and second light-emitting portions in parallel, featuring resistance and electrostatic capacity members to adjust color temperature, and includes LED elements and phosphors for uniform color mixing, with a PWM signal type dimmer for further control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate power sources are used for different light-emitting elements, then color temperature adjustment is achieved, but device complexity and wiring patterns increase

Engineering Contradiction:
Improvecolor temperature adjustmentVSAvoidwiring patterns
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple light-emitting elements (first and second light-emitting portions with different luminescent colors) into a single integrated structure that can be powered by one power source. The elements are arranged in parallel within the same device housing, allowing unified power supply while maintaining independent optical characteristics for color temperature control.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single power source is designed to supply power to multiple types of light-emitting elements simultaneously. The device structure allows one power source to serve multiple functions by powering both the first light-emitting portion and the second light-emitting portion, which have different luminescent characteristics, thereby achieving universal power supply capability.

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

2Adaptability or versatility

If multiple light-emitting elements with different luminescent colors are used, then color temperature variation is achieved, but light color uniformity deteriorates

Engineering Contradiction:
Improvecolor temperature variationVSAvoidlight color uniformity
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by assigning different luminescent characteristics to different regions (first light-emitting portion with first luminescent color, second light-emitting portion with second luminescent color). Each region maintains its specific optical properties while contributing to the overall color temperature adjustment, allowing spatial differentiation of light characteristics.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transitions from single-color light emission to multi-color light emission by adding a new dimension of color variation. By incorporating light-emitting elements with different luminescent colors (e.g., blue and yellow-green), the device achieves color temperature adjustment through spectral composition rather than just intensity modulation.

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

3Device complexity

If LEDs of different luminescent colors are connected in parallel, then single power source operation is achieved, but temperature characteristics and lifetime uniformity worsen

Engineering Contradiction:
Improvepower source configurationVSAvoidtemperature characteristics uniformity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent compensates for different temperature characteristics of LEDs with different luminescent colors by adjusting operating parameters (current allocation, resistance values) for each light-emitting portion. The resistance members are specifically selected to balance the temperature rise and lifetime characteristics across different LED types, ensuring uniform reliability despite parallel connection of dissimilar elements.

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 adjustment of color temperature using a single power source, achieving uniform and adjustable light emission with improved directivity and reduced complexity in the light emitting device structure.

Implementation Method 1

wavelength-converting members that cover the respective light-emitting elements and that convert light emitted from the respective light-emitting elements into light with different wavelengths

Methodology Applied
Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentEP3226313B1Light emitting device and lighting device including the same
Publication Date: 2019.12.18 SHARP KK
  • EP3226313B1 patent drawingFigure 1~2
  • EP3226313B1 patent drawingFigure 3~5
  • EP3226313B1 patent drawingFigure 6

AI summary

A light emitting device that can adjust a color temperature by using power supply from a single power source and a lighting device including the light emitting device are provided. A light emitting device includes a reflector formed of a housing having an opening at an upper portion, an anode electrode terminal and a cathode electrode terminal that are disposed on a side wall or a bottom surface of the housing, and a first light-emitting portion and a second light-emitting portion that are arranged in parallel inside the reflector so as to be electrically connected to the anode electrode terminal and the cathode electrode terminal and that are adjacent to each other. The first light-emitting portion includes a first resistance member. The color temperature of light emitted from an entire light-emitting portion including the first light-emitting portion and the second light-emitting portion can be adjusted.