Brightness enhancement of LED using selective ray angular recycling

摘要

Light that is emitted from an LED chip at a first angle of incidence or less relative to the LED chip is permitted to leave the LED package. Light emitted from the LED chip at an angle of incidence greater than that is kept from leaving the LED package and is recycled back within the LED package. The recycled light is reemitted from the LED package after its angle of incidence relative to the LED chip has been changed, for example by passing it through a diffuser.