"A sign of judging the quality of LED car lights is: there is no focus lens, if it has, then it is sure that the light type is good, if not, then astigmatism, poor light type, it is recommended not to buy." In the network, we often see a variety of tricks, buy LED car lights friends sometimes difficult to distinguish between the true and false. One of the tips just mentioned is about lenses.
So, do LED car lights have to be equipped with concentrating lenses, and what are the advantages and disadvantages of them? Let's talk about this topic today.
This has to start with the predecessors of LED lamps, halogen lamps and xenon lamps.
Halogen lamp is an evolutionary version of incandescent lamp. It uses tungsten filament to electrify and stimulate thermal radiation luminescence. The difference is that it injects halogen gas such as iodine or bromine into the lamp. At high temperature, the sublimated tungsten filament reacts with halogen. After cooling, tungsten will re-solidify on the tungsten filament, forming a balanced cycle, avoiding premature breakage of tungsten filament, making the lamp longer and brighter.
High intensity Discharge (HID) is a kind of inert gas mixture filled with xenon, which activates inert gas in quartz tube and makes it emit arc light through 23000 volt high voltage current. This is different from halogen lamps, which do not rely on filament thermal radiation but generate arc light. It can obtain higher color temperature and brightness at lower power.
Concentrating lenses flourished with the popularity of xenon lamps.
Solution of non-focus
If you have been working on lighting lectures, you may remember that I once talked about three elements of LED lights. Brightness, Concentration and Installation. It is necessary to obtain satisfactory brightness under the condition of low output power as far as possible; to focus the light, the light type emitted is good, and the sense of paving is good; it is necessary to facilitate installation and heat dissipation. In fact, these three elements are also suitable for other car lights.
Xenon lamp has incomparable technical advantages compared with halogen lamp, but it also has a huge disadvantage, that is, not focusing. In the first phase of our Yishida Lighting Seminar, we said that the point light source had better concentrate light, because it is 360 degrees of light, which can be effectively done through the lamp bowl; while the area light source is not conducive to concentrating light, so the LED car lights, like the LED lights of Yishida, should be treated by various technologies to make the gap between the beads thin, making it as similar to the point light source as possible; Xenon gas lamp. Concentrating light is more difficult than LED, because it is the arc light emitted by the high-voltage inert gas in the quartz tube after the current is passed, similar to lightning, this light has no rules, how light emits, willful!
It is in order to solve the problem that xenon lamp can not focus, technology gods in the front of the xenon lamp, and specially equipped with a lens, this lens to focus the scattered light, light and directivity is better, and finally we can get the light type that we can use at night.
Advantages and Disadvantages of Lens
Many car owners feel that the car lights with lenses are smart enough, commonly known as "bull's eye headlights". They are energetic, but they do not know that there are advantages and disadvantages.
First of all, although the lens is only a convex lens like half a glass sphere, when light passes through it, it will cause damage because of its internal structure. Compared with the lamp without lens, no matter what brand or brand of lamp you are, you will generally lose about 30% of the brightness. After a long time, the lens will generally be covered with dust. Laboratory testing of the old lens can only reach 40% of the original brightness. ! And it's hard to clean up.