What is the meaning of lens coating and classification by surface treatment
The coating of spectacle lenses refers to the use of physical and chemical methods to coat the surface of spectacle lenses with a certain thickness of single-layer or multi-layer optical films, so that the lenses can obtain some new and excellent properties that they did not originally possess. Currently, there are mainly:
1. Anti-reflection coating (anti-reflection coating) is a multilayer coating
No matter the light transmittance of resin or glass lens can not reach 100%, part of the light will be absorbed by the lens. The surface reflects back, the higher the refractive index of the lens, the higher the reflectivity. Resin 4%, glass 4.3%.
The reflection of the lens can reduce the light transmittance and form an interference image on the retina, which affects the quality of imaging and affects the appearance of the wearer's optical lens. For example, the appearance of the lens is obviously vortex, and the eyes of the wearer cannot be seen by the opposite light.
The anti-reflection coating is the most commonly used optical coating. It is based on the wave of light and the principle of interference, so that the reflected light of the mirror and the reflected light of the coating interfere with each other. eliminate. Different film layers selectively eliminate the reflection of light in the corresponding wavelength band to remove interference light, and increase visible light transmittance to improve image quality. Make the image clearer and reduce visual fatigue. It can also selectively reduce the penetration of harmful rays in certain wavelength bands, such as ultraviolet rays, X-rays, etc., to reduce the damage of these rays to the eyes and protect the eyes from their harm.
At present, the anti-reflection film of the resin lens of the optical lens has as many as nine layers, and the reflectance has been reduced to about 0.2%, so that the light transmittance of the resin lens can reach 99% the above. Greatly improve the quality of imaging and obtain the best correction effect.
2. Top film (waterproof film, anti-fog film)
Due to the technical requirements of anti-reflection film, the gap between the molecules of the film is large, and the surface of the lens is easy to contain dirt and dirt.
The top membrane material has small molecular particles and small gaps between the molecules, which makes the surface of the lens more smooth and adds water-proof, anti-fog, dust-proof and other anti-pollution functions.
3. Wear-resistant film (commonly known as hard film)
The base of the resin lens is soft, and the focusing lens is slid on a hard object. The anti-reflection coating on the lens is very It is easy to produce scratches, which will affect the light transmittance of the lens and the effect of the film. Therefore, in order to improve the wear resistance of the lens, the researchers used the soaking process to plate a material with high hardness and not brittle cracking on the surface of the organic lens, that is, a hard-wear film.
According to surface treatment points:
1. No surface treatment:
No surface treatment such as filming.
2. Wear-resistant film (commonly known as hard film):
Spectacle lenses will cause lens wear in daily use. For example, if a dirty lens cloth wipes the dust on the lens, it is easy to Scratches on the lens surface. Therefore, it is necessary to plate a wear-resistant film. The aspheric mirror wear-resistant film contains an organic matrix and inorganic ultrafine particles including silicon, so that the wear-resistant film has toughness and at the same time increases the hardness.
3. Anti-reflection coating:
The spectacle lens forms an optical system with the eye, and the spectacle lens coated with the anti-reflection coating has a significant improvement effect on vision. The principle is based on the fluctuation and interference of light, so that the reflected light generated on the front and back surfaces of the film interferes with each other, so as to cancel out and achieve the effect of anti-reflection.
4. Anti-fouling film:
After the multi-layer anti-reflection film is coated on the surface of the lens, the lens is particularly prone to stains. Therefore, a top film with oil and water resistance is coated on the anti-reflection coating