Organic Electroluminescent Element for Dual-Temperature Color Rendering
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Solution Overview
Problem
Conventional organic electroluminescent elements struggle to provide both high color rendering properties for food display at low temperatures and general indoor lighting at room temperature, leading to increased costs and the need for multiple lighting designs.
Innovation Solution
The development of an organic electroluminescent element with a specific structure, including multiple light emitting layers with phosphorescent and fluorescent dopants, which maintains optimal color rendering indices across a temperature range of 5°C to 60°C, ensuring consistent appearance and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a fluorescent lamp is used as a light source, then it can provide illumination, but it has a narrow emission spectrum making it difficult to obtain various color rendering properties
Solution Approach 1:
The patent employs multiple phosphors with different emission characteristics (yellow phosphor, red phosphor, green phosphor) combined in a single phosphor layer. This composite phosphor system broadens the emission spectrum coverage and enables high color rendering properties across different temperature conditions, resolving the limitation of narrow spectrum in conventional fluorescent lamps.
2Adaptability or versatility
If fluorescent lamps with different color rendering properties are developed for different lighting uses, then color rendering requirements are met, but it increases the cost of light sources
Solution Approach 1:
The patent designs a universal phosphor composition that can simultaneously satisfy both food display lighting requirements (high special color rendering index R13 at low temperature) and general indoor lighting requirements (high general color rendering index Ra at room temperature). This single multi-functional light source eliminates the need for developing and manufacturing separate lamps for different applications, thereby reducing costs.
Solution Approach 2:
The patent utilizes temperature-dependent emission characteristics of phosphors to achieve different color rendering properties under different operating temperatures. By selecting phosphors whose emission spectra change favorably with temperature, the same light source automatically adapts to provide optimal color rendering for food display at low temperatures and general lighting at room temperatures.
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
This solution allows for a single organic electroluminescent element to effectively illuminate food at low temperatures while providing high general and special color rendering indices at room temperature, reducing the need for multiple lighting designs and lowering production costs.
Implementation Method 1
Organic electroluminescent elements (organic light emitting diodes) are attracting intention as next-generation light sources
Implementation Method 2
a light emitting layer is constituted by a hole transporting light emitting layer in which a hole transporting material to which a first fluorescent material is added serves as a matrix
Implementation Method 3
an electron transporting light emitting layer in which an electron transporting material to which a second fluorescent material is added serves as a matrix
Data Source
AI summary
The object of the present invention is to provide an organic electroluminescent element suitable for both food lighting at a low temperature and indoor lighting at room temperature. The organic electroluminescent element according to the present invention has such characteristics that a maximum of a general color rendering index Ra in a range of an element temperature of 5° C. to 60° C. is present in a range of the element temperature of 15° C. to 35° C. and that at least one of maxima of special color rendering indexes R10, R11, R12, and R13 in the range of the element temperature of 5° C. to 60° C. is present in a range of the element temperature of 5° C. to 35° C.