Solid State Light Emitter Package High CRI Design
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Solution Overview
Problem
Current solid state light emitter packages using blue, green, and red LEDs have a limited Color Rendering Index (CRI) due to their narrow light emission spectra, making them unsuitable for main functional lighting and only suitable for decorative purposes, as they often produce light with a color point close to the black body line but with poor color rendering quality.
Innovation Solution
A solid state light emitter package comprising a blue emitting die, a red emitting die, and a further die that emits ultraviolet, violet, or blue light, combined with a luminescent converter that absorbs and converts the further light into greenish light, along with an optical element for mixing the colors, achieving a high CRI by ensuring a wide emission color distribution and a color point close to the black body line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If blue, green, and red LED dies are combined to generate multiple colors, then the gamut of emitted colors is enlarged, but the Color Rendering Index (CRI) remains relatively low due to narrow emission spectra
Solution Approach 1:
The patent combines multiple LED dies (blue, green, red) with a phosphor coating material to create a composite light emission system. The phosphor material converts blue LED light into yellow light, and when combined with the green and red LED emissions, produces a broader spectrum with improved CRI while maintaining large color gamut.
2Manufacturing precision
If blue LED dies covered with yellow phosphor are used to generate white light, then the color rendering index is improved, but the gamut of emitted colors is limited
Solution Approach 1:
The patent merges the advantages of both approaches by combining blue LEDs with yellow phosphor (for good CRI) with additional green and red LED dies (for expanded gamut). This hybrid configuration achieves both high color rendering index and large color gamut simultaneously.
3Use of energy by moving object
If narrow spectrum LED dies are used to achieve specific color points near the black body line, then energy efficiency is improved, but the color rendering quality deteriorates
Solution Approach 1:
The patent changes the spectral parameters by introducing phosphor materials with specific emission characteristics. The phosphor converts narrow-band blue LED light into broader-spectrum yellow light, and the combination with green and red LEDs creates a wide spectrum that maintains energy efficiency while dramatically improving color rendering quality.
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 enables the production of high-quality light with a high CRI and a large gamut, allowing for a wide range of colors to be generated, including white light with various color temperatures, while maintaining a uniform color distribution, thus enhancing the lighting's functionality beyond decorative uses.
Implementation Method 1
The luminescent material is configured to absorb light within an absorption color distribution and to convert a portion of the absorbed light towards greenish light according to an emission color distribution
Implementation Method 2
The optical element is configured for mixing a portion of the greenish light with at least one of a portion of the violet/blue light and a portion of the red light before the light is emitted through the light exit window
Data Source
AI summary
A solid state light emitter package (200), a light emitting device, a flexible LED strip and a luminaire are provided. The solid state light emitter package comprising: i) at least three solid state light emitter dies (132, 142, 152) which emit violet/blue light, red light and further light, respectively, ii) a luminescent converter (120) with luminescent material, iii) an optical element (102, 105) for mixing at least portion of the light of the different colors of light and iv) a light exit window (114). The luminescent material at least partially converts the further light towards greenish light having a peak wavelength in the green or cyan spectral range and has a color emission distribution that is wide enough such that the solid state light emitter package is capable of emitting light with a high enough Color Rendering Index. The Color Rendering Index relates to light that has a color point close to the black body line.