Aspheric lenses are aspheric lenses, that is to say The surface shape of the lens may be quadric or cubic surface, and the cubic surface is also called free-form surface.
The lens shape ofAspheric lenses is calculated by Jinque and grinded by precision machine. In the design process, Congfen takes into account the above correction factors, so one aspheric lens can achieve the correction of aberration of multiple spherical lenses. Manufacturing lens with Aspheric lenses can effectively reduce the number of lenses and therefore reduce the volume of lens, and also improve the imaging accuracy and transmittance of lens, Color restoration is more accurate
The main feature of aspheric lens is that it can improve the refractive index of light at the edge of the lens, so as to make the image of the object more detailed. The Aspheric lenses is applied to the monitoring lens for the first time, and the performance of this kind of lens is greatly improved. At present, the Aspheric lenses combines hybrid aspheric element with low scattering (LD) lens to obtain excellent optical properties. Among them, LD lens has the property of unparallel optical quality, which can effectively reduce the color difference phenomenon that reduces the contrast and sharpness of the image.
This aspheric lens has high gogoyi requirements:
On the one hand, the optical properties of optical resin can only reach Zui excellence by ensuring appropriate management during the casting process; on the other hand, the physical properties of fragile LD lenses need to ensure Zui precision processing accuracy during the polishing and coating process.
The light at the edge of the ordinary spherical lens blurs the imaging points due to refraction, resulting in halo; The light at the edge of the aspheric lens is just focused at a point through the refraction of the high-order surface, so the imaging point is fechangjinque. Therefore, the imaging quality of aspheric lens is improved. In addition, since one aspheric lens can replace the combination of multiple spherical lenses, the volume of the lens is correspondingly reduced and the light transmittance is also improved.
The high-end surveillance camera lens is a compound lens, which develops to multiple groups and pieces in structure. No matter how complex its structure is, its lens group is composed of convergent lens and divergent lens. Convergent lens is convex lens, divergent lens is concave lens, and non-linear convex lens or concave lens always has a spherical surface. Therefore, the lens with spherical surface is called "spherical lens". Although modern spherical lenses have been widely designed and processed by computers, they are also made of new high-quality optical glass. However, it is difficult to fundamentally eliminate all kinds of spherical aberrations, chromatic aberrations and other aberrations. Especially for long focal length and large aperture lens, various aberrations are particularly serious. To fundamentally solve these problems, Zui's good way is to design a precise and accurate aspheric lens.
The characteristics of aspheric lens are that it can improve the imaging power (resolution) of photographic lens. It is convenient to manufacture large aperture lens, especially large aperture zoom lens, which is particularly important for increasing zoom multiple, making lens high quality and miniaturization. Therefore, aspheric lens has almost become the development trend of lens. As early as the early 1950s, some people proposed that the best Zui scheme to improve the imaging quality of the lens was to make the photographic lens aspheric. The above figure is a comparison between a spherical lens and an aspheric lens under light focusing.
