White LED Light Emitting Device with Selective Color Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light emitting devices face challenges in reducing chromaticity variation and improving light emission efficiency, particularly when using LEDs that emit colors other than white, as they require conversion to white light, leading to optical energy loss and inefficient color reproduction.
Innovation Solution
A light emitting device comprising a white light emitting unit, a red light emitting unit with a red coating member, and a green light emitting unit with a green coating member, each using a LED unit that emits white light, with an adjustment coating member to fine-tune chromaticity, allowing for reduced chromaticity variations and improved efficiency by minimizing optical losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If lights of various colors are converted into white light using a resin cap with fluorescent material, then chromaticity uniformity is improved, but light emission efficiency deteriorates due to optical energy loss during conversion
Solution Approach 1:
Instead of converting colored light to white light (conventional approach), the patent inverts the approach by using white light LEDs directly and converting to specific colors only when needed using color filters or phosphors. This reversal minimizes unnecessary optical conversions and energy losses while maintaining chromaticity uniformity.
Solution Approach 2:
The patent extracts the color conversion function from the resin cap and applies it selectively only to specific LED chips that require color adjustment. By separating the white light source from color conversion, the system avoids converting all colored lights to white and then re-converting, thereby reducing energy loss.
2Manufacturing precision
If a high concentration of fluorescent material is used in the resin cap to convert light effectively, then chromaticity control is improved, but light emission efficiency deteriorates greatly due to increased optical energy loss
Solution Approach 1:
The patent applies color conversion selectively to specific LED chips based on their individual chromaticity requirements. By using local quality adjustment rather than uniform conversion for all chips, the system achieves precise chromaticity control while minimizing overall energy loss from optical conversions.
Solution Approach 2:
The patent adjusts chromaticity parameters by selectively applying color filters or phosphors with specific characteristics to individual LED chips. By changing the parameters of color conversion only where necessary and optimizing the concentration and type of fluorescent materials, the system achieves precise chromaticity control while minimizing energy loss.
3Adaptability or versatility
If white light from RGB LEDs is converted into different colors through a resin cap, then color variety is improved, but optical energy is lost due to double conversion
Solution Approach 1:
The patent inverts the conventional color conversion approach by using white light LEDs as the primary source and applying color filters or phosphors selectively. This reversal eliminates the double conversion process (colored light to white, then white to colored) and achieves color variety with minimal optical energy loss.
Solution Approach 2:
The patent extracts the color conversion function and applies it only to specific LED chips that require color adjustment. By separating the white light generation from color conversion and applying conversion selectively, the system maintains color variety while minimizing unnecessary optical energy loss from repeated conversions.
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 effectively reduces chromaticity variations in mixed colors and enhances light emission efficiency by utilizing the LED unit's white light directly and adjusting chromaticity as needed, while allowing for precise color temperature control and reduced energy loss.
Implementation Method 1
a red coating member having a red fluorescent material which converts the white light from the second light source into a red light
Implementation Method 2
a green coating member having a green fluorescent material which converts the white light from the third light source into a green light
Data Source
AI summary
A light emitting device includes a white light emitting unit including a first light source emitting a white light; a red light emitting unit including a second light source emitting a white light and a red coating member having a red fluorescent material which converts the white light from the second light source into a red light; and a green light emitting unit including a third light source emitting a white light and a green coating member having a green fluorescent material which converts the white light from the third light source into a green light. The light emitting device further includes a driver for individually driving the white, the red and the green light emitting unit.