Headlight Development

It is said that the first automobile headlights were household hand lamps. In 1887, when a driver was lost on a dark field, a farmer led him home with a hand lamp. In 1898, the Columbia electric car used electricity for the headlights and taillights, so the headlight was born. The original headlights could not be dimmed, so they were somewhat dazzling during the meeting, and in order to overcome this shortcoming, additional photometric regulators were later used. This headlight can move in a vertical direction, but the driver must get out of the car to move the fixture. From the early development of acetylene gas headlamps to today's free surface reflector gas discharge headlamps, almost 120 years, its evolution process is as follows: The first generation - acetylene headlights Headlights have a high profile brightness, the brightness of the acetylene gas flame is twice as high as the brightness of the electric light source at that time, so the car headlights used before 1925 are almost all acetylene headlights. In 1913, the gas-filled incandescent light bulb with spiral filament came out, because of its high brightness, to the electric light source headlamp opened up a broad prospect. However, due to the constraints of the automotive electrical equipment system at that time, it was not until 1925 that electrical lighting was widely used. The third generation - dual wick headlights with a high profile brightness of the electric headlights with inflatable bulbs installed on the car, there is a serious problem in the intersection of the car due to the strong light of the headlights caused by the driver dazzle and lead to traffic accidents and crashes. Therefore, the design of headlights put forward two incompatible requirements: one is how to make the road and the height of at least 2-2.5m obstacles within a distance of not less than 100m to get good lighting; Another is how to make oncoming drivers less dazzled. This dazzling problem when the car meets is still the most difficult problem to solve in the automotive lighting technology. In order to solve the problem of dazzling cars, in 1924, after the invention of double-light wick headlights in Europe, the United States also appeared headlights with double-filament bulbs. However, the optical system structure principle of headlamps with non-blinding low light in Europe and the United States is not the same. The difference in the light bulb is that the shape and position of the filament are different: the difference in the light matching mirror is that the pattern and calculation of the refractive unit are different, and therefore, the light distribution of the near light is also different. The near-light system is divided into two kinds: the European system and the American system, and the coordination of the two systems is one of the major issues in the development of automotive lighting in the world today. The fourth generation - asymmetric low light headlamp double light wick headlamp system is a symmetrical low light system, the left and right sides of the near light type are exactly the same, so the left and right sides of the driving are applicable. However, when the driving light (far light) changes to the meeting light (near light), the visual distance is shortened, forcing the speed to decrease. In order to solve the problem that in the process of meeting, the headlamp does not produce dazzling, but also to ensure that the road has good lighting, the United States invented the asymmetric headlamp in 1932, which is centered on the benchmark axis, the beam is divided into two parts, and the landing distance of the side near the car is short (that is, the beam is low, so as to prevent dazzle), and the landing distance of the other side of the beam is long (that is, the beam is raised). Thereby increasing visibility). The fifth generation - h4 tungsten halogen headlights The first batch of automotive headlights equipped with tungsten halogen bulbs were produced by the French "Spebe" company in 1964, and the filament allowed working temperature is higher than that of ordinary incandescent bulbs, the light efficiency is increased by about 50%, and the life is doubled. The sixth generation - hid headlights Modern automotive headlights represented by hid headlights have undergone a series of major changes in terms of luminous principle, structural form and manufacturing materials. hid Xenon headlamp is a high voltage breakdown of inert gas ionization and light, which produces strong illuminance, high color temperature, strong penetration, and energy saving, is the ideal car headlamp light source. The latest research results in the United States show that in the next five years, white high-power led technology will substantially replace the current various lighting products, and will be applicable to a variety of automotive lighting, including: headlights] brake lights, fog lights, emergency lights, interior lighting, etc. led has many advantages such as high safety, smooth operation, power saving, long life and so on, which is a development trend of future vehicle lighting.