Photochromic lens quality problems and testing methods
In order to standardize the photochromic lenses product quality, in 1988, the state formulates the standard photochromic glass lens blank, until today there are many manufacturers in the production of photochromic blank and lenses, photochromic glass lenses are also constantly changing, the development of colored glass lens is according to this principle, that is looking for adding a variety of optical glass colorant glass brings a different color, for a variety of monochromatic light selectively absorb or filtering. Its purpose is mainly used for shading and various protective goggles, make his eyes from the harmful rays and sand, chemicals, toxic gas, etc, have the effect of protecting our eyes. The characteristics of common colored glass lenses and use the following table 7 4. The picture shows the characteristics of the colored glass lenses and feature and USES grey chart name coloring such as cobalt, copper, iron, nickel oxide uniform absorption spectral lines, absorb ultraviolet light, infrared, sunglasses, pilot wearing green auger, copper, chromium, iron, cerium oxide absorb ultraviolet light, infrared, such as goggles, Gas welding, welding, argon arc welding) Cobalt blue, such as iron, copper, manganese oxide anti glare, goggles, High temperature furnace cellar) Red, cadmium sulphide selenide cadmium fluorescent dazzling, goggles, Medical X-ray) Yellow cadmium sulphide and cerium, titanium oxide absorb ultraviolet light and night vision goggles or rain, fog, wearing a drivers and related terms color components: the color of the color composition of different lead to change color is so different, such as part of the dark brown color piece include silica, alumina and boron oxide, also joined the cobalt, nickel and manganese coloring solution is made and be become. Photochromic lens color wants even, color reaction to fast. Discoloration speed: the lens, has different kinds of photosensitizer, discoloration speed is not the same. Darker rate: dark rate depends mainly on the lens material of optical density, usually from a few seconds to several minutes from big light transmittance is very little light transmittance. Fading rate: fade rate depending on the composition of the lens and the discoloration of heat treatment. At the same time it will take a few seconds to several minutes from light transmittance is great to light transmittance. Color change when the temperature at which the heat treatment: the color of the color change along with the temperature change. The speed of change color when heat treatment: the speed of the color change along with the temperature change. Lens light transmittance: photochromic lens color is mainly by pushing the ultraviolet ray in the environment, therefore, there is no uv in the environment, to visible light transmittance can reach 84%, in this case, the photochromic lenses can be used as a visual corrective lenses, just like the plain white lenses. Uv absorption rate: general international traffic change grey or tea on the lens to under 380 nm uv absorption rate can reach more than 95%, to 400 nm uv absorption rate can reach more than 85%. In addition, at present most of the color lenses for multi-layer vacuum coating treatment and prevent electromagnetic waves, known as the EMI coating processing, through such processing of color lens will look more transparent, light transmittance is better, for a variety of appliances such as computers, mobile phones have isolation effect of electromagnetic waves emitted. Second, the main test project 1. Colour and lustre, 1) Colored glasses lens pairing may not have clear off color; ( 2) Photochromic glass lenses per pair matching must base color is consistent, colour and lustre is consistent after color change. 2. Surface quality and internal flaws, top coke, prism degrees shall conform to that stipulated in the GB10810 corresponding requirements, namely: ( 1) At a reference point as the center, in the area with a diameter of 30 mm can't affect vision of huo guang, defects such as spiral; ( 2) The lens surface should be smooth, clear perspective, the surface are not allowed to have orange peel and the mould. 3. Photochromic lens color changing faster, alterant longer service life. 4. Photochromic lenses must also have the impression of a shallow, so that it has enough transparency in indoor. 5. The photochromic lenses when using illuminant D65, luminous transmittance lens is not less than 3%. Additional requirements ( Applicable to lenses while driving) : if you have a luminous transmittance was less than 8%, are not used to driving or road use. Daylight use illuminant D65, daytime driving light transmittance & gt; 8% as the design reference; Night use illuminant D65, lens to use for driving at night, visible light transmittance over 75% for design reference. The photochromic lenses to ball IS014899 standard, ANSI 280. 3 standards, as well as AS1067. 1 standard. 6. In accordance with GB10810. 1, observes through the lens of red, yellow and green traffic lights motto, standard specified in the corresponding to the traffic signal of the projection ratio for: on a red signal should be 8% or more; The yellow and green signal should be 6% or higher. If various traffic signal projection ratio is too low, then decreased to signal recognition ability, also is one of the hidden trouble of traffic accidents, so the standard is more important. 7. Other performance of the photochromic lenses should comply with the general optical lens of the national or industrial standards. 8. Frame: should be compliance with all requirements of GB/T14214 ( See the frames for the national standard) 。 9. Assembly accuracy and cosmetic requirement: should conform to the specified requirements of GB13511.