Optical lens should be very familiar to people in machine vision industry, because lens is an essential part of machine vision detection system. As for the principle of lens, we should also have some understanding. In some of our lenses, there may be some abnormal images. Let's get to know.
In machine vision system, optical lens is equivalent to human eyes, its main function is to focus the optical image of the target on the photosensitive array of image sensor (camera). All the image information processed by the vision system is obtained through the lens, and the quality of the lens directly affects the overall performance of the vision system. Once there is a serious loss of information in the imaging system, it is very difficult to try to recover in the later link. One of the key technologies of vision system is to select industrial lens and design imaging optical path.
There are many kinds of optical lenses, which can be divided into short focal length, medium focal length, long focal length and zoom lens according to the focal length, wide angle, standard and telephoto lens according to the field of view; In terms of structure, it can also be divided into fixed aperture fixed focus lens, manual aperture fixed focus lens, automatic aperture fixed focus lens, manual zoom lens, automatic aperture electric zoom lens, electric three variable lens (aperture, focal length and focus are all available), etc.
Optical lens imaging will be more or less distorted. Large distortion will bring great trouble to the vision system, which should be considered in detail in the imaging design, including the selection of lens with small distortion, the effective field of view only taking the center field of view with small distortion and so on. Another characteristic of lens is its spectral characteristic, which is mainly affected by the interference characteristic of lens coating and the absorption characteristic of material. It is required that the light with the highest resolution of the lens should match the brightness wavelength and the wavelength received by the CCD device, and the light transmittance of the optical lens should be improved as much as possible. Some special effects can be achieved by selecting proper filters in the imaging system. In addition, the design of imaging optical path also needs to pay attention to the influence of various stray light.
Lens is also an essential part of TV monitoring. Lens and CCD industrial camera can image the long-distance target on the CCD target surface of industrial camera, and then convert the optical image formed by the optical imaging system into video / digital signal through it.
The high-quality machine vision lens of Dongzheng optics adopts ultra-low distortion design, low distortion rate and various optical correction methods to minimize the occurrence of aberrations, so that it can maintain high MTF value in the frequency band with high spatial frequency, high contrast definition, strong mechanical design of lens, and adjusted locking device, which are very suitable for factory automation and machine vision Vision, intelligent detection, image processing and other occasions with very high requirements for image quality can be used with all kinds of industrial cameras, widely used in medical industry, printing detection, LCD detection, glass detection, solar detection, lithium battery detection, circuit board detection and many other fields, high-precision measurement, detection, recognition and other industrial machine vision and image processing systems.
