Any glass produces reflections, including flat and radial glass. Therefore, like many optical instruments, such as lenses (including glasses), in order to reduce reflections and increase transmittance, it is necessary to coat the glass.
A light blue-purple color appears on the coated glass, typically for camera or telescope lenses. Magnesium fluoride (MgF2) is usually used for coating treatment. The refractive index of magnesium fluoride is 1.38, which is much lower than that of sapphire glass (1.52 for ordinary glass and 1.76 for sapphire). The more the refractive index is, the lower the refractive index of sapphire glass is. The higher, the stronger the reflection. Therefore, the effect of sapphire watch glass coating will be better. Magnesium fluoride (MgF2) has the smallest refractive index, only 1.38. Magnesium fluoride coating can reduce the reflectivity of light from 4% to 1.8%, which also increases the transmittance. Of course, in order to improve the transmittance, multilayer coating can also be used to enhance the transmittance, that is, both sides of the glass are coated.
Magnesium Fluoride Coating Material:
According to the information, the Mohs hardness of magnesium fluoride (MgF2) crystal is grade 6, which is general hardness, but because of the thin film thickness, it is easy to be worn out. The coating on the common glasses is also very easy to be worn off, which also depends on the specific use. For example, when the glasses are washed only with detergent and water at ordinary times, the maintenance time is much longer than that wiped directly with cloth, and so is the watch glass.
Especially for watches with large glass diameter and radian, it is more necessary to increase the coating treatment. The coating can not completely eliminate the reflection, but can only reduce. Some watches make a mark to indicate that the glass of the watch has been coated. For example, Omega watches, on the card or tag of the watch, use a circle with a letter A inside, while AA watches indicate that both sides of the glass are coated. There are many reflective points on the watch, including the case, dial and needle. They are either golden or silver. Therefore, coating is also one of the measures to make it more convenient to wear a watch. The coating on the glass of the watch will not be as obvious as that on the lens of the camera. Some of them are difficult to see.
Watch glass inner coating will not be worn, when the glass coating damage, careful look will have a pattern of mottling, but also need to pay attention to watch in long-term storage, we must pay attention to moisture-proof, long-term wet environment, glass surface will be mildewed, but also destroy the coating. Therefore, it is important to keep desiccants and to avoid dampness in the case.
网站地图 千站地图 Copyright©2017泰州市爱特斯光学材料有限公司.Allrightsreserved本司主营:硫化锌,五氧化三钛,混合物膜料,五氧化二铌,五氧化二钽,硒化锌,一氧化硅