| 摘要 |
A lamp having a candle-like appearance and using one or more light-emitting diodes (LEDs) as its light source is presented. The candle-like appearance arises because light is emitted from only a small volume at or near the center of the bulb. The heat sink and control electronics are located outside the bulb of the lamp. Inside the bulb is a set of secondary optics that guide the light from one or more LEDs to an emission point at a prescribed location in the interior of the bulb. The secondary optics include a light pipe that guides light away from the LED chip, and a volume scattering element that receives the light from the light pipe and scatters it into various directions. The volume scattering element is made from a transparent base material, and includes transparent particles of a predetermined size and refractive index. Because the lamp is typically used in an overhead position, such as in a hanging chandelier, the density of particles in the volume scattering element, the particle size and the particle refractive index are chosen to produce a scattering pattern that directs more light downward (toward the base of the bulb) than upward, while maintaining a reasonable efficiency (fraction of produced light that successfully exits the lamp). Simulation results are presented. |
