An explore explanation of Halogen, HID, LED, and Laser Headlights
When driving on the road at night, we will meet the people drive their vehicle with poor high-beam headlights. Our heart is crashed. We can’t wait to reflecting a tenflod light to them for revenge. But before we complain the problem of high-beam headlights, do we really understand the type and structure of them? Today, I would like to take a deep learning in them.
- Reflective halogen light
We have to talk about incandescent light before saying halogen light. The principle of the incandescent light is to conduct enough current to the filament. When the filament is heated to incandescent state, it will begin to glow. But its drawback is the short life-span. So humans add halogen gas into the bulb. Sublimed tungsten filaments get chemical reaction with halogens at high temperatures. The cooled tungsten will resolidify on the tungsten filaments.
Through the reactions, it comes to a balanced cycle to avoid premature fracture of the tungsten filaments. Its life-span takes longer than incandescent bulbs.
Since the light bulb glows in all position, it will cause a issue. That is the light can not concentrate on the road, most of light don’t work on right purpose. Also It will often flash to the driver of the vehicle. So human beings creat something to surround the bulb, it is called reflector. It can help to gather light. The front lamp doesn’t look good if only with a reflector. So gradually, the car manufacturer added lens to make the front lamp look better. The lens improve headlight bulb in nice appearance and spotlight. But because halogen bulb is not bright enough, when putting in projector, it is going to be dimmer than before. Halogen bulb is not suitable to work together with projector. Now halogen bulbs normally still work with reflector.
- HID headlight
The defect of halogen light is low brightness, so we sometimes name it candle light. For this reason, humans invented another automotive light, High intensity Discharge HID.
HID bulb is full of Inert gas mixture includes Xenon. It breakdowns the xenon by high pressure to produce an arc between two electrode and release light. There is no tungsten filament in it, so it can be used for a longer time. The lifetime of HID is 10 times longer than traditional halogen bulbs and the brightness is three times than it.
When replace with HID, the difference is obvious. Many car owners would like to install HID for their car. If the modification did not do well, it is very easy to have problems because of its high brightness. Some original cars do not have lens on front headlamp, when install HID bulb, the original reflector could not gather the light because the position and shape of the bulb is changed. At this time, the light emitted by xenon is scattered. It will glare the driver so that he can’ see the road condition clearly.
As we all know the HID headlights are usually white or even bluish. The penetration of yellow light is better than white light and blue one. So the penetration of HID lighting is weaker than traditional halogen light in rainy day. People will change golden fog headlight after installing HID headlight in order to see the road clearly in rainy and foggy day.
- LED headlight
People still did not satisfied with HID headlight, so they use another light in the car---LED (Light-emitting diode). Why LED have more advantage than Halogen and HID headlight? Here are its merits as below:
- Energy conservation
LED are twice as efficient as fluorescent bulbs. In the car, LED energy consumption is only 1/20 of halogen lights.
- Long life
At present, LED car headlight can last for 50000 hours when halogen lights just can last for only about 3000 hours.
- Good durability
Due to the simple structure of the LED lights, the shock resistance is better and it can adapt to various environments.
- Small volume
LED components are small, so it is easy to be placed in compact space. It can meet the requirements of the lights for the manufacturers.
- Quick response
The lighting of the LED is microsecond, which can be used in the car for better response.
- Low requirement for environment
LED units can be driven by low voltage direct current and it is low load.
When we mention led headlight, your guys may remind another stuff, Audi OEM matrix LED headlight. By light up and crush out with single LED light, Audi created a dynamic turn signal light. This LED matrix headlight group can detect the traffic vehicles ahead. It will automatically adjust or close several LED monomers in the light group to keep the other party from the light influence. The LED element gives more development for the vehicle light group to make them more capacity and advanced.
- Laser headlight
However, humans are still not satisfied with the current headlight technology. There is then the manufacturer created a newest headlight---laser headlight. Laser diode is the core of laser headlight. The laser headlight releases light and controls the direction of the light beam through a lens. Laser diodes have most of the advantages of LED. And the brightness is higher than LED. A single laser headlight element is smaller than LED’s, it's 1/100 of the LED size. The benefits of laser headlights are high brightness and long illumination distance.
The use of laser headlights is supported by LED headlights. Although the irradiation distance of laser headlight is far away and bright, the range of irradiation is narrow, it needs LED headlight to supplyment the light. The world's first mass production car used laser headlights is Audi R8 LMX. The biggest feature of this car is the use of laser headlights. BMW i8 also install laser headlights. BMW and Audi are now equipped with laser headlights on their mass production cars.
In fact, there are not many types of headlights, the total classification is actually halogen headlight, HID and LED (the laser headlights are not popular, which is not mentioned here), and it is easy to distinguish them. But whether it's a HID headlight or LED headlight, some of the most basic things we need to obey, that is, the civilization in using lights. Even if your lights are really awesome, there's no need to keep your high-beam headlights on at all times. It is no benefit for both us and others.