OPTICAL DEVICE FOR LED-BASED LIGHT-BULB SUBSTITUTE

摘要

An optical device is for spatially displacing the output of a light-emitting diode (LED) and coupling the output to a predominantly spherical emission pattern produced at a useftul height above the LED. The device is made of a transparent dielectric material, such as an injection-molded plastic. It comprises a lower transfer section that receives the LED's light from below and an upper ejector section that receives the transferred light and spreads it spherically. One or more LEDs. are optically coupled to the bottom of the transfer section, which operates by total internal reflection upon their entire hemispherical emission. One embodiment operates as a flashlight-bulb substitute with the ejector section radiating onto a parabolic reflector, which forms the beam. Thus hemisphencally emitting LEDs can be used in parabolic-mirror flashlights wherein these LEDs by themselves may be unsuitable for that role.