US Patent 10501342 UV-C water purification device

Methods and apparatus are provided for ultraviolet (UV) water purification, comprising UV-C LED modules having improved light extraction efficiency. UV-C LED dies (12) are solidly coupled to associated translucent output windows (14), such that light is transmitted directly from light-emitting surface(s) of the dies (12) to output window(s) (14) of the LED package—without propagation across interstitial air gaps. Gas-to-solid (and solid-to-gas) light transition boundaries are thus eliminated, significantly reducing the amount of light lost through inter-medium boundary reflection, and thereby increasing efficiency of light extraction.