First of all, halogen headlights, which we have seen are generally ancient, the principle may be traced back to the era of Edison. It is characterized by a warm yellow light, low brightness, can only meet the basic use, but it is not without advantages, in rainy or foggy days, warm yellow light penetration is good. Next is the xenon headlamp, which is based on the principle of high-pressure ionization of xenon in the bulb, thus emitting light. It is characterized by high brightness, which is about several times that of halogen lamps. The efficiency of converting electric energy into light energy has also been greatly improved, that is, it is bright and energy-saving. However, its structure is complex and its cost is high, so it is common in high configuration vehicles. LED headlamp, because of its fast lighting speed, used to be used in brake lamp before, but now LED light source is also used in headlamp. Nowadays, LED headlights often play the role of light box, signboard, indicator light and backlight of various electrical appliances. They are also important components of taillights, high-level stop lights and daytime running lights. The advantages of LED headlamp for automobile, LED light source (not limited to headlamp) has the following advantages: energy saving, long service life, good durability, small size of LED components, compact and easy to layout and design, fast response speed, low brightness attenuation and so on. In addition to the three mainstream headlights, laser headlights have become the new favorite of automobile manufacturers in recent years. In addition to the high efficiency, long life, fast response, strong stability and many other advantages of LED headlight, the diode light source of laser headlight is far less than that of LED lamp, so the designer has a better space to play. The modeling of laser headlamp is not only restricted to the traditional impression of automobile headlamp in the past, but also can be seen in many concept cars. Although the advantages of laser headlamp are more advanced than LED headlamp, but the cost is high, so laser headlamp can only be used in some luxury brand models now, and it can't be "happy with the people".