Nested LED Filament Enclosures for Spectral Light Conversion

The patent implements a nested enclosing structure where a first enclosing structure containing blue LEDs is placed inside a second enclosing structure containing wavelength-converting elements. This nested arrangement allows both structures to work together efficiently - the inner structure extracts blue light while the outer structure converts it to other wavelengths, achieving high overall efficiency without requiring either structure to be excessively thick or complex on its own.

The patent divides the LED filament into two distinct functional segments: a first enclosing structure containing blue LEDs that emits blue light, and a second enclosing structure containing wavelength-converting elements that convert the blue light to other wavelengths. This segmentation allows each structure to be optimized for its specific function, making the overall system more versatile in terms of spectral control while keeping individual components relatively simple and manageable.

The patent applies local quality by using wavelength-converting elements selectively in the second enclosing structure rather than uniformly across the entire LED filament. This allows certain regions to convert blue light to warm white or other colors, creating the aesthetic appearance of traditional incandescent filaments in specific areas, while other regions maintain high blue light emission for efficiency. This localized approach enables both aesthetic quality and efficiency to coexist.