Patent ID: 8686636
Filing Date: 2014-04-01
Classification: F21S,H01L

Abstract:
1. A lamp assembly including an illumination direction, comprising: a light source including an LED element with an emission surface; and a projection optical system for projecting an image of the light source in the illumination direction so that a desired light distribution pattern is formed on a virtual vertical screen disposed in front of the lamp assembly, wherein the light source has a rectangular shape having long sides and short sides, and is configured to provide a luminance distribution on the emission surface such that a luminance peak portion is provided substantially at one of the long sides, the lamp assembly is configured to project an image corresponding to the luminance peak portion toward a predetermined area in the desired light distribution pattern, the LED element has a first long side and a second long side and includes the projection optical system is configured to project an image of the light source in the illumination direction as a plurality of light source images so that the image of the luminance peak portion corresponding to the n electrode is positioned on one side of the light distribution pattern, thereby forming the light distribution pattern for a headlamp including a cut-off line formed of the images of the luminance peak portions of the plurality of the light source images on a virtual vertical screen located a certain distance away from the lamp assembly in the illumination direction, and a plurality of concave and/or convex structural units are formed on the surface of the n-type semiconductor layer so that a density of the structural units is increased from the second long side of the LED element toward the n electrode.