The role of the lens in the optical system is: focusing, collimating and imaging. The lens usually needs to be coated with antireflection coating to reduce the reflection on the surface of the lens, which can reduce the loss of light energy and make the image more clear.
Lens is an optical element made of transparent materials (such as glass, crystal, etc.), which will affect the curvature of the wavefront of light. It is a device that can converge or disperse light, and the resulting images have real and virtual images. It is widely used in various fields such as security, car wearing, digital camera, laser, optical instrument and so on.
Various common colorless optical glasses including fused silica, calcium fluoride, magnesium fluoride, silicon, germanium, zinc selenide and other materials; and various wave bands Plano-convex lenses, bi-convex lenses, plano-concave lenses, bi-concave lenses, super hemispherical lenses, small ball lenses, meniscus lenses, cylindrical lenses, rod lenses, cemented lenses, etc.
The imaging law of lens and convex lens
1. The lens is represented by the lens symbol (a line segment has two A V-shaped mark), draw the main optical axis, mark the optical center and focal point, according to the two refracted rays of the three special rays of the lens (usually the light that has passed through the optical center and the light parallel to the main optical axis is better) At the intersection point, the characteristics of the image formed by the lens (such as virtual reality, size, front and back, etc.) can be obtained.
2, when the lens is imaging, all the rays of light emitted by each point on the object and hitting the lens are imaged in the same position, blocking a part, and does not affect the direction of the lens. The imaging of other light, so you can still see the complete image, but because the light hitting the image is reduced, the brightness of the image on the screen will become darker.
The various lenses we have seen are made using optical processing technology and optical lenses. This processing requires multiple steps to complete.
In optical cold processing, the cleaning of lenses mainly refers to the cleaning of residual polishing fluid, adhesives, and protective materials after lens polishing; lens edging oil, glass Cleaning of powder; cleaning of fingerprints, saliva circle and various attachments before lens coating. The traditional cleaning method is to use wiping materials (gauze, dust-free paper) and chemical reagents (gasoline, ethanol, acetone, ether) to soak, wipe and other means to manually clean.
This method is time-consuming and labor-intensive, and has poor cleanliness. It is obviously not suitable for the modern large-scale optical cold processing industry. This forces people to find a mechanized cleaning method instead. Therefore, ultrasonic cleaning technology gradually entered the optical cold processing industry and showed its talents, which further promoted the development of the optical cold processing industry focusing lens.
The basic principle of ultrasonic cleaning technology can be roughly regarded as the use of the huge force generated by the ultrasonic field to promote a series of physical and chemical changes in the substance with the cooperation of the washing medium In order to achieve the purpose of cleaning.
When high-frequency vibration higher than the sound wave (28～40khz) is transmitted to the cleaning medium, the liquid medium generates a nearly vacuum cavity bubble under the high-frequency vibration, the cavity In the process of collision, merging, and extinction of bubbles, the liquid can instantly generate a pressure of several thousand atmospheres in a local area. Such a large pressure causes a series of physical and chemical changes in the surrounding materials. This effect is called'cavitation':
1. Cavitation can break the chemical pool bonds of material molecules, causing various physical changes (dissolution, adsorption, Emulsification, dispersion) and chemical change aspheric mirrors (oxidation, reduction, decomposition, compounding), etc.
2. When the natural frequency of the cavity bubble is equal to the ultrasonic frequency, resonance can occur, and a large amount of heat energy is accumulated in the resonant cavity bubble, which is enough to make the surrounding Physical and chemical changes are caused by the breaking of chemical bonds of substances.
3. When the cavity bubble is formed, a large potential difference is generated between the two bubble walls, which causes a discharge, which causes the bubble in the cavity to activate and then the surrounding material is activated, thereby Make physical and chemical changes in matter.
Ultrasonic field provides huge energy for cleaning, but it also needs chemical lotion as a medium. Generally, chemical lotions are divided into two categories. One is organic solvents, which are mainly based on the chemical principles of similar compatibility. For organic substances such as: binders (asphalt, rosin, etc.), protective materials (asphalt, resin, etc.), grinding Dissolve the lubricant on the side.