Car headlight classification
Considering the actual situation, we only introduce the mainstream products that we can buy in the used car market as well as the new car market nowadays.
First of all, the most common is also the most simple, ordinary reflective halogen lights, which we all know very well, divided into far and near light integrated and far and near light separation two. In the picture is the Polo Jinxiao / Jinzhu separated headlights, low beam with H7 halogen bulbs, and high beam H1 halogen bulbs.
Among them, the general use of H4 bulbs in the near and far light-reflective headlights lighting effect is relatively poor, sales of a large number of Fido and my own Mazda 2 are using this headlight. The advantage is cheap, whether the cost of the bulb or the cost of the lamp body is cheaper than the split type, but the disadvantage is also very obvious, the bulb brightness is low, and near and far light can not be lit at the same time, belongs to the worst lighting effect on the market at present a kind of car lights.
There is also some halogen near and far light integrated lights with lenses, to solve the problem of diffuse light but the general brightness. Near and far light at the same time to light depends on the light is dependent on the bulb or lens's internal shade. In addition, there are also halogen split headlights with lenses, the irradiation effect is generally the best in halogen lights.
Some older high-end cars will be equipped with xenon headlights (a kind of inert gas, in the case of high-voltage electricity, will be white-blue light), the exposure to excellent brightness. But because of the xenon headlights in the work of all the locations where the gas will glow, belonging to the body light source, there is no way to control the light pattern with only reflective bowls as halogen lamps, the original factory will be equipped with lenses.
But the xenon lamp has a feature that is slow to light up, the initial brightness of the light is not enough, and sometimes even green, so it is not suitable for the high beam with flashing function. Few manufacturers will use xenon lights to do near and far light as one, usually, xenon only for low beam use, when the high beam is always on, hit the lens inside the open baffle as high beam use, in addition to additional halogen lights for flashing tips.
Now more popular is the LED headlights, LED headlights have the advantage of fast lighting, high brightness, and low energy consumption, and because of the small size of LED light-emitting units, can be used as a point source. The disadvantage is afraid of high temperature, there is a possibility that the brightness will decay over time, damage can usually only replace the assembly, and the cost is expensive.
From a macro point of view, LED headlights are divided into two types, one is the relatively inexpensive reflective LED headlights, the PCB board for installing LED beads is located at the top of the headlights, the beads are down, and the reflective bowl size is small and a bowl corresponds to a group of beads. The light pattern can also be more aggregated, but to prevent dazzling, the general reflective bowl headlight irradiation height will be adjusted relatively low, such as the Accord, BMW 3 Series, and Volkswagen Bolero MQB are so. But despite this these headlights paving effect and brightness are better than the traditional halogen headlights, the biggest problem is that the near light is difficult to shine far, limited visibility distance.
And when the LED headlights with lenses after the effect is no shortcomings, and because the LED light-emitting units are very small, so you can achieve, for example, matrix projection and other additional functions.
Currently, the most advanced headlights should be laser headlights, and LED headlights, compared to the laser headlights in brightness, efficiency and volume have some improvement, but the cost is too expensive, so the application is not widespread, here we will not expand on it.
