Anti-wear film began in the early 1970s, when the glass lens is not easy to grind because of its high hardness nickel oxide, organic lens is too soft, so easy to wear. Plated quartz material in the vacuum conditions in the organic surface of the lens, forming a layer of very hard wear-resistant film, but because of its thermal expansion coefficient of the film base material does not match, it is easy stripping and film embitterment, and therefore anti- wear effect is not ideal.
After the 1980s, researchers found that theoretically produced by wear mechanism is not only related to the hardness, the dual character of the film material has a hardness deformation , i.e., the higher the hardness of some materials, but the deformation is small, and some low hardness, but with a large deformation. The abrasion resistance of the second generation of membrane technology is through the immersion process method in the organic surface of the lens coated with a high hardness and difficult to embitterment of the material.
The third generation of wear-resistant membrane technology developed since the 1990s, mainly to the less reflective film on the organic lens coating wear resistance. Organic lens hardness of the film base and the hardness of the antireflection film is very different, the new theory is that a layer of anti-wear coating, so that the lens can have a dampening effect by gravel friction between the need and not prone to scratches. Between the third-generation anti-wear coating materials hardness ranged from less reflective film and the lens substrate hardness, low friction coefficient, and difficult to brittle fracture.
The fourth generation of anti-membrane technology is the use of silicon atoms, hardening solution containing both the organic substrate, but also contains inorganic ultra fine particles of matter, including silicon, wear-resistant film with toughness and hardness. Modern plating the main anti-wear film technology immersion lens after a multi-channel cleaning, immersion plus hardware solution, after a certain time, brought to a certain speed. At this rate the viscosity of hard and fight to play a decisive role in the wear of the thickness of the neodymium fluoride film. Filed after the polymerization in the oven about 100 C, 4-5 hours, the coating thickness of 3-5 microns.
Antireflection coating of the lens surface is a very thin inorganic metal oxide materials (less than 1 micron thick), hard and brittle. When deposited on glass lenses, due to the film base is relatively hard, gravel across its top, the film is relatively prone to scratches; antireflection coating deposited on organic lenses, due to the film base is relatively soft, gravel in the membrane across the layer, the film is very prone to scratches. Organic lenses must be plated antireflection coating plated wear-resistant membrane, and the hardness of the two films must match.
When light is through the lens before and after the surface, it will not only has refraction but also the reflection. The reflection of this lens front surface will make people see a white surface of the lens when they watch the eye of people who wearing glasses. When taking photos this reflex will also seriously affects the appearance of those who wears glasses.Source:http://www.mhcocm.com