In the past, many cars had headlight washers, which looked very advanced. But those who have used it know that this thing just uses a nozzle to spray glass water on the headlights, and it is difficult to wash off the stains. So why are there so many cars still in use?
Among them, it is estimated that many people will be surprised: the headlamp cleaning device is mainly for dust removal, and it is not really for cleaning the lampshade.
If you pay attention, you will notice that in the early years, all vehicles equipped with headlight washers used xenon headlights, specifically xenon low beams.
Because there is a provision in the national standard: if the luminous flux of a single light source of the low beam lamp exceeds 2000 lumens, it must be equipped with a headlamp cleaning device.
The reason is that dust on the lampshade will produce glare, and the brighter the light source, the more severe the glare. Therefore, for safety reasons, there is such a regulation, and 2000 lumens is a hurdle. Since the high beam itself is direct, it is not required.
It is difficult for the luminous flux of a single bulb of halogen headlights to exceed 20,000 lumens, and xenon headlights are very sad, because the luminous flux of one bulb can easily exceed 2,000 lumens, so after this regulation came into effect, as long as the cars equipped with xenon low beam are almost equipped with headlight cleaning devices. It only needs to rinse the dust off the lampshade at start-up to avoid glare as much as possible.
In recent years, many cars that were originally equipped with headlight cleaning devices have canceled this configuration. The main reason is the popularity of LED headlights.
Because although the LED headlights are also very bright, the national standard requires that "the luminous flux of a single light source is greater than 2000 lumens" before it needs to be equipped with a headlight cleaning device. The LED headlights of some cars will be made into a combined structure of multiple light sources, so that even if its overall luminous flux is greater than 2000 lumens, the luminous flux of a single light source is less than this limit, so there is no need to be forced to equip headlight cleaning devices.