The film-adding workshop is the same as the hardening workshop, which has high requirements for the environment. All adopt a dust-free environment and positive pressure airflow, making dust inaccessible. The temperature and humidity of the workshop are strictly monitored and adjusted by instruments, because the coating depends heavily on the cleanliness of the lens, and the slightly dusty lens surface is easy to fall off after coating. The surface bright spots are formed, so the staff wear special electrostatic clothing to prevent the dust from the hair from falling on the lenses when the external environment enters the workshop. Before coating, the British lenses should be cleaned piece by piece with a high-pressure air gun to remove the hidden surface Impurities, and some personnel re-check whether the lens meets the coating conditions, put the qualified lens on the coating cover, and the operator in the coating workshop cannot even talk casually, so as to avoid saliva contaminating the lens.
After the previous steps, the lens is put into the imported vacuum coating machine. The perfect airtightness can make the machine reach a high vacuum state. The optical lens is mainly used for ion vacuum Coating technology, advanced ion source bombardment (using argon ions) to make the lens surface clean and free of unevenness, so that the sputtered film can be fully bonded to the lens, so as to achieve a firm effect, fully automatic The production can strictly control the color consistency of the film. In addition to being beautiful and having various colors, the main function of the coated lens is to reduce the reflection and increase the reflection, eliminate the reflection phenomenon that will occur on the surface of the uncoated lens, and increase the access to people. The light from the eyes makes the wearer see more clearly and brightly. The seven to nine layers of coating materials enable the final lens to have high strength, 96%-99% high transmittance, anti-electromagnetic wave radiation, waterproof and anti-fog and other multiple effects.
After each batch of coated lenses, the adhesion, wear resistance and firmness of the lens film must be sampled. The testing requirements must be higher than the national standard for wear resistance. As an example, use 0000# steel wool, weighing about 75 optical lens 0g, and grind back for 1 minute at a certain speed, and the frequency is about 120 times. The result of the test is to observe whether there are signs of abrasion with the inner eye, and wear test. The purpose is to make it difficult for the wearer to scratch when using the wiper, so that the hardness of the lens is qualified. Of course, the firmness of the film is also very important. Use 4.5% salt water (pure water) to cook at 100 degrees Celsius. For 12 minutes, immerse it in cold water for 20 seconds every two minutes, then put it in boiling salt water, repeat 6 times to observe whether there is any peeling off, and only qualified products inspected and tested can be approved to enter the packaging department, ready to be imported Library.
Scattering refers to a phenomenon in which light is spread in all directions. It is generally produced on the surface of a solid or inside a transparent material. In theory, there is no scattering on the surface of the spectacle lens, because the surface of the lens is quite smooth after polishing and other processes, which eliminates this phenomenon. For spectacle lenses with a focus lens, the scattering inside the lens is also very limited and can usually be ignored.
But in the following cases, the light scattering phenomenon will affect the optical imaging of the lens. For example, when the lens is soiled due to external pollution or blurred due to oil stains, the surface of the lens is not smooth, which will cause light scattering and affect optical imaging, which must be considered. In addition, if the internal quality of the lens is not good, scattered light will be generated in the lens, and the lens will appear yellow or milky white, which should also be considered at this time.
Diffraction refers to the process of changing the direction of travel when a light wave encounters a small obstacle while traveling. This phenomenon. In the use of glasses, the phenomenon of diffraction must arouse great attention. Because if the glasses are used improperly or the surface of the lens is worn, diffraction will occur, which will cause abnormal interference to the imaging of the lens.
Aspherical mirror mechanical properties
Mechanical properties usually reflect the characteristics of solid materials, which specify the mass and volume of the material And the size and resistance of the material to deformation and impact. Our common reflections of the mechanical properties of the lens are density, hardness, elastic modulus, impact resistance and resistance to breaking point.
Density refers to the ratio of mass to volume of a substance. The quantity has no unit, it is a reference standard for solids under standard conditions.
The hardness refers to the force necessary to achieve a certain degree of denaturation. Hardness is one of the important factors to measure the quality of spectacle lenses. Lens materials of different hardness have different processing methods and technical requirements.
(3) Elastic modulus
Elastic modulus is produced when pressure occurs and the original shape is restored after pressure is eliminated The ratio between the corresponding deformations, usually refers to the ratio of height or volume.
(4) Impact resistance