In the whole development of electric light source, the headlight basically adopts parabolic reflector. The mirror rotates on its axis in a parabola. Its purpose is to collect and concentrate light from the bulb and shoot it out parallel to the axis of the light bulb. Lighting distribution in compliance with regulatory requirements is achieved by the combined action of bulbs, reflectors and light distribution. This kind of reflector was used for a long time, about half a century or so.