As the eyes of the car, the headlights play a vital role in driving safety at night. With the development of automobile science and technology, the types of automobile headlights are also continuously improved. From halogen headlights to laser headlights, they are successively applied to different models. Different types of headlamp sources have their own advantages and disadvantages. Now let's introduce the characteristics of four common headlamp sources.
1、 Halogen automobile headlamp light source
Halogen headlights are one of the most common automotive headlights used in automobiles at present. Halogen headlights have a development history of 40 years. Halogen headlights are actually improved from incandescent lamps. In fact, adding halogen gas into incandescent bulbs can make halogen bulbs more durable than white incandescent bulbs. Due to the omni-directional direction of halogen bulbs, they belong to astigmatic light sources. People use reflectors to gather light, Therefore, we usually use halogen lamp as light source, and the lamp group that gathers light through reflector is called reflective halogen lamp. As long as you see a bulb in your headlight, only the reflector, that is the reflective halogen lamp. Halogen lamps have such characteristics. The brightness of warm yellow light is low and can only irradiate 30-40 meters, but its low color temperature determines its strong penetration ability (it is very practical in rainy and foggy days), low cost, small volume, simple replacement and so on.
2、 Xenon automotive headlamp light source (HID)
In fact, the arc generated by the high-voltage xenon gas is discharged between the two xenon lamps at the moment of 12V. In fact, the high-voltage xenon gas is discharged between the two xenon gas rectifiers to form a high-voltage arc. It is precisely because the xenon headlamp is the light emitted by the arc and has no tungsten wire. Its service life is very long, which can reach 10 times that of the halogen lamp, and the brightness can reach 3 times that of the halogen lamp. Because its brightness is much higher than that of halogen lamp, some owners of the original car whose headlights are halogen lamps will be converted into xenon headlights. The author believes that if the original car is a reflective halogen headlamp, due to its structure, it is changed into xenon headlights without lens, the reflector can not effectively gather light, and the light is scattered, which will lead to the driver's inability to see the road clearly and flash into the eyes of the driver of the opposite car, Therefore, the xenon headlights without lenses are all hooligans. The lens halogen lamp is changed to xenon headlamp. The counter trend of xenon headlamp is that its light is white and blue, and its color is not as strong as the Yellow penetration of halogen lamp. In rainy and foggy weather, the irradiation ability is not as good as halogen headlamp.
3、 LED automobile headlamp light source
LED is the abbreviation of light emitting diode, which is translated into Chinese as light emitting diode. In the past, it was commonly used in tail lamp, turn signal lamp and daytime running lamp. Due to its advantages, LED is also used as automobile headlamp in more and more models. Its optical structure is similar to xenon lamp. LED light can be concentrated into parallel light through reflecting bowl and lens. The advantages of LED headlamp are obvious: ① energy saving and high luminous efficiency, Its energy consumption is only one twentieth of that of traditional halogen lamps. ② its service life is long, and the service life of LED can reach about 50000 hours, which is almost twice that of xenon headlights. ③ its application degree is high. Due to its good seismic and impact resistance of electronic components, it can be used in a variety of environments. ④ its volume is small, and the volume of LED components is small, which can almost meet the layout and modeling design of various lamp factories. ④ its response speed is fast, The lighting of LED is at the microsecond level. ⑤ the brightness attenuation is small, and the brightness attenuation of LED is far less than that of halogen lamp. ⑥ the requirements for the use environment are low. The LED unit can be driven only by low-voltage DC, and the load is small. Unlike xenon lamp, it also needs boost device.
4、 Laser automobile headlamp light source
Laser headlights are made in recent years. Laser headlights send out light beams through laser diodes, and then control the direction of light beams through lenses. Laser headlamp has many advantages of LED headlamp, and its brightness is higher than that of LED. Moreover, a single laser headlamp element is much smaller than that of LED element, which is only one percent of the size of LED element. The advantage of laser headlamp is its high brightness and long irradiation distance. Generally, the laser headlamp needs to be used together with the LED headlamp. Although the laser headlamp has a long irradiation distance and is bright, but the irradiation range is narrow, it still needs the LED headlamp to supplement the light.