Double-light-extraction-rate light distribution technology for projection type lower-beam headlamp

The invention discloses a double-light-extraction-rate light distribution technology for a projection type lower-beam headlamp and relates to the technical field of motor vehicle headlamps. Particularly, the double-light-extraction-rate light distribution technology for the projection type lower-beam headlamp can improve the luminous energy utilization rate of a traditional projection type headlamp by twice. According to the double-light-extraction-rate light distribution technology for the projection type lower-beam headlamp, a hemispherical reflection cup is arranged on the lower half portion of an ellipsoid reflection cup, a light source is arranged at the center of a hemispherical surface, light rays emitted by the light source are reflected by the hemispherical reflection cup and return along an original light path, and on the return way, the light rays illuminate the ellipsoid reflection cup on the upper half portion after passing by the position of a point light source. By the adoption of the double-li