Difference between automotive lighting and foreign deposits

The common lighting fixtures in the market are basically divided into two groups. The domestically produced lamps occupy ultra-low prices, and the imported lamps become synonymous with burning packages. The quality difference between domestically produced lamps and imported lamps is mainly reflected in the following three aspects.

Light type accuracy

Most domestically-made reflector bowls are not computer-aided design shapes. Instead, they use the mold-turning model to directly pirate products from molded products. For more detailed things, few manufacturers actually study in depth. For a light fixture, a final light pattern does not only depend on the design of the reflector bowl, but also the lens part (transparent glass or polyester cover on the front of the lamp). It is entirely possible to completely reproduce the appearance of the two, but when it comes to the refractive index of the lens and the non-pointed light source provided by the halogen filament, the accuracy of the light pattern is difficult to duplicate.

We know that the refractive index affects the direction of the light passing through the lens; and the distance between the lens and the reflection bowl also directly affects the accuracy of the outgoing light direction. The latter is easy to copy, but the refractive index of the lens depends on the material itself, which is not an analysis of precision instruments, and it is difficult to achieve complete reproduction.

Again, for the light sources we use now? ? For halogen lamps, it is not an ideal point source. As we all know, filaments are of a certain length, and it is impossible to use simple high school physics knowledge to deal with the reflection of such light sources. If high school physics knowledge can be used directly, we will buy a spherical glass shell. After cutting it in half, the inner surface will be coated with a reflective film. The lamp will be placed on the center of the sphere and can be used as a spotlight. Now.

To accurately control the final light pattern of a non-point light source, it is necessary to rely on professional auxiliary design software. After the software calculates the light path of the filament point by point, the light emitted from different positions of the filament at the light drop point is superimposed on the point. Only after the installation of the HID, many people found that the reason for the light-type divergence is that the luminous point of the HID light source cannot completely coincide with the halogen lamp. Usually it is a curved folding line similar to the lightning. same). Even when you use a light bulb that is produced in a non-standard format, it will cause a deviation between the final exit light pattern and the design light pattern. A good luminaire will let you obtain most of the luminous flux in its design light pattern, and only a few luminous fluxes fall outside the design area.

High temperature resistance and oxidation resistance of the reflective bowl coating

Reflective bowl coating, the pros and cons, the most intuitive experience is the size of the reflectance. Normally, we can now purchase new car lights with good reflection effects. We can find a lot of intuitive quality problems such as air bubbles, impurities, and protrusions on the surface of the reflective bowl of some of the lights with poor coating quality. Normally, products of normal quality will never allow you to see this, because this situation is defective for a general quality control system. However, the real place where we can distinguish quality products and vice-products is the intrinsic quality of the reflective film.

Modern coating technology In order to save production costs and improve reflection efficiency, aluminum film is usually used, and aluminum itself is easily oxidized due to long-term exposure to air to form a non-reflective aluminum oxide layer; at the same time, in order to enable the coating to reflect the metal Substrate bonding is solid and usually based on polymer materials. When the polymer material is exposed to ultraviolet light, it will rapidly age, resulting in a phenomenon of reflection bowl whitening. However, this does not mean that our existing reflector bowl will be subject to aging due to solar radiation. The ultraviolet ray is a drizzle for polymer materials, and the UV source that causes it to age rapidly is precisely the light source that we use to provide lighting. ? ? light bulb. The light source we use now is not a single wavelength, and its wavelength is continuous, but we can't see the light in the infrared and ultraviolet regions. Therefore, many light sources produced by major manufacturers are specially specified: UVcut.

Another intrinsic quality of the coating is the performance of its high temperature resistance (of course, this is also related to the thermal design of the lamp itself). The halogen lamps we use are of thermoluminescence. The normal operating temperature of the filaments is 2000 degrees Celsius. In the confined space of the lamps, such a heat source can heat the air in the lamps to above 150 degrees, and the infrared part of the continuous light waves is also Need to reflect through the coating (reflectivity is impossible to reach 100%), heat conduction, convection, radiation three heat transfer modes are heating the coating, continuous heating for a long time will make Li Gui and Li Yu appear out of shape. I have used domestic fog lamp products, and none of the products have retained their coating on the base of their reflective bowl after 10 hours of night driving, and they are firmly attached. Only a small area of ​​blistering occurs. Excellent quality products.

Lens impact resistance, transparency, and resistance to sudden changes in temperature

The so-called lens is the transparent cover in front of the luminaire. It is usually made of two types of materials: glass and polyester. The biggest advantage of polyester products lies in its impact resistance. The gravel rolled up by the tires of the previous car on the gravel roads shatters the glass lampshades and the windshield glass. I am afraid that many car-lovers suffer from heartaches, and polyester products encounter In this case, usually only a small white pit will be left, or a few tiny crack roads will appear, which will not affect the use of the entire headlights.

In addition, the ability of polyester materials to withstand sudden changes in temperature is also unmatched by glass materials. After all, the brittleness of glass is much higher than that of polyester. When we walk through a section of rain and fog with lights on, if the quality of the glass does not pass, In that case, simply wiping the lamp surface with a wet paper towel will bring endless trouble to the journey behind you, because the lamp surface will burst into pieces. The transparency of the glass material is better than that of the polyester material in the long-term stability. If the quality of the polyester material is too low, it will be aged in a short period of time (between half a year and one year). At this time, the lens color will turn yellow and accompanied There is a phenomenon of bleaching, and glass is not affected by external conditions such as ultraviolet rays, and continues to maintain its initial transparency. In addition, students who pay attention to the light and light type need to pay attention, not the glass and the polyester lens can be directly replaced with the same size, because even if the two are even the same pattern, the difference between the refractive index of the two materials will cause the change of light type.