What are the knowledge of aspheric optical lenses and optical glass
Optical lenses can generally be divided into spherical lenses (SPHERICALLENS) and aspheric lenses (ASPHERICALLENS).
Spherical lens, the center range of the mirror surface is the normal imaging focal length, and the light refraction angle at the edge of the mirror surface is restricted by the shape of the spherical surface and deviates from the normal focal length track. Therefore, the acceptable imaging light range of this kind of optical lens is relatively small, and the F-number is large. As a result, the light entering the lens is relatively small.
aspherical lens, because of the convex aspherical lens, the light entering the camera through the center and edge of the mirror has the same focal length, which will make the lens The acceptable imaging light range is larger and the F number is smaller, so more light enters the camera. As a result, the laser focusing lens will increase the overall sensitivity. The purpose is to reduce the aberration of the optical correction lens, make the lens flatter, and reduce the lens magnification. Obtain clearer, thinner, and lighter quality lenses.
Because the surface of the aspheric lens is convex, the processing cost and technology are much higher than that of the spherical lens. In order to save costs, although the photosensitive effect of aspherical lenses is better than that of spherical lenses, most of the lenses currently on the market used in the surveillance field use spherical optical lenses.
Optical lenses are divided into spherical lenses and cylindrical lenses. The curved surface of a spherical lens is a part of the spherical surface, and is classified into a convex spherical lens or a concave spherical lens according to the convergence or separation of parallel light rays. Convex spherical optical lenses are used to correct hyperopia, presbyopia or aphakia. Concave spherical lenses are used to correct myopia. The curved surface of cylindrical laser protective lens is a part of the cylinder. The axis of the cylindrical lens is parallel to the cylinder and has no refractive power in the direction of the axis. The direction perpendicular to the axis has the greatest refractive power, and it is divided into convex cylindrical lenses or concave cylindrical lenses, which are used to correct hyperopia or myopia astigmatism, respectively.
Lens will become dirty after long use. If you wipe it with paper towel or cloth casually, it will damage the lens due to scratches and affect the quality and appearance of the lens. Optical lens cleaning machine is an ultrasonic cleaning equipment, suitable for cleaning lenses, spectacle frames and glassware. The heating temperature is automatically adjustable; there is a safety device; the ultrasonic output frequency can be fine-tuned according to different working conditions; during the cleaning process, the ultrasonic frequency is swept back and forth within a reasonable range to drive the cleaning fluid to form a fine backflow, so that the workpiece is dirty When the laser collimator is peeled off by ultrasonic, it is quickly taken away from the surface of the workpiece, which improves cleaning efficiency.
Optical glass is a kind of glass. It can change the direction of light transmission. It can be used to make lenses and mirrors in optical instruments. There are many varieties of optical glass. Let's take a look at some classifications of optical glass.
1, colorless optical glass
There are specific requirements for optical constants, with high transmittance in the visible area, no selection Absorbs the characteristics of coloring. According to the Abbe number, it is subdivided into coronal and flint glass, and each type is divided into several types according to the refractive index unevenness, and they are placed in order according to the refractive index. Mostly used as lenses, prisms, mirrors, etc. of telescopes, microscopes, cameras, etc.
2, anti-radiation optical glass
has a large absorption capacity for high-energy radiation, mainly optical lenses are used in nuclear industry, medical field, etc. as shielding and prying window materials.
3. Radiation resistant optical glass
Under certain gamma-ray and X-ray irradiation, the visible area is transparent The overrate changes less, and the variety and trademark are the same as colorless optical glass, which is used to make optical instruments and spying windows under high-energy radiation.
4. Colored optical glass
is also called filter glass. It has selective absorption and transmission functions for specific wavelengths in the ultraviolet, visible and infrared regions. According to the spectral characteristics, it is divided into three types: selective absorption, cut-off and neutral gray. It is mainly used to make filters.
5, ultraviolet and infrared optical glass
has a specific optical constant and high transmittance in the ultraviolet or infrared band , Used as ultraviolet and infrared optical instruments or as window materials.