Classification of machine vision industrial lens "mm" focal length

Today with the rapid development of machine vision technology, we are in the process of developing machine vision systems. The selection of the core components of industrial cameras, machine vision light sources, and industrial lenses is indispensable. Then we will start with the classification of industrial lenses today and introduce the details of industrial lenses. Classification. There are many classification methods and varieties of industrial lenses. The interfaces and uses of industrial lenses are now classified as follows. 1. Classified by industrial lens interface 1. CCTV (C-MOUNT) Also known as C-mount industrial lens, it is an industrial lens widely used in machine vision systems at present. It has the advantages of light weight, small size, low price, and many varieties. Its interface rib parameter: nominal diameter = 1 ", pitch: 32 teeth. A kind of change interface of C installation is called CS-mount, which is different from C-MOUNT only in the distance between the positioning surface of the industrial lens and the photosensitive surface of the image sensor. C-MOUNT is, and CS-mount is, the difference between them is 5mm. Industrial lens products on the market, such as the ZML series of small zoom industrial lenses, all use standard C-mount. The CS-MOUNT interface is designed for new CCDs. With the development of CCDs, the integration level is getting higher and higher, and the photosensitive array of the same resolution is smaller. Therefore, CS-MOUNT is more suitable for the smaller effective photosensitive sensor size. Industrial video camera. Industrial cameras with CS interface can be connected with C and CS interfaces, but C-installed industrial lenses need to be equipped with an adapter ring; industrial cameras with C-interfaces can only be connected with C-installed industrial lenses, but not with CS Install industrial lens connection, otherwise not only can not get good focus, but also may damage the CCD target surface. 2. 35mm camera industrial lens This kind of industrial lens is the 35mm industrial camera industrial lens used in daily life. It is a very good industrial lens in terms of cost performance. There are many industrial cameras and line scan CCDs that need to be equipped with this industrial lens. One disadvantage of the 35mm industrial lens is the bayonet fixing method. When this fixed method is used in a vibrating environment, the industrial lens will move. So in the machine vision system, 35mm camera industrial lens is not a good choice. 2. Classified by equivalent focal length of industrial lens 1. Wide-angle industrial lens An industrial lens with an equivalent focal length smaller than the standard focal length (50mm). It is characterized by short working distance WD, large depth of field, large viewing angle, and usually the distortion is barrel distortion. 2. Long focal length industrial lens The equivalent focal length exceeds 200mm, the working distance is long, the magnification is large, and the distortion is usually pincushion distortion. 3. Medium focal length industrial lens The industrial lens commonly used in machine vision systems has a focal length of about 50mm, which is between a wide-angle industrial lens and a long-focus industrial lens. Normally, the distortion correction is better. 4. Telecentric industrial lens In machine vision systems, the size of objects is often very important. However, when the general industrial lens is imaging, the image of the object far away from the industrial lens is smaller, and the image of the close-up object of the same size is larger. As a result, measurement errors are produced. The telecentric industrial lens is designed to eliminate this error, so that objects of the same size and different distances and nears can obtain the same size image on the imaging surface. The telecentric lens is divided into single telecentric lens and double telecentric lens. The BTOS bi-telecentric lens developed by the telecentric optical system technology for high-precision measurement is eye-catching. 5. Macro industrial lens Industrial lens for shooting smaller objects, it has a large industrial lens magnification ratio. 3. Classified according to the functions of industrial lenses 1. Variable focal length industrial lens It is relative to the fixed focus industrial lens. Through the mutual movement of the lenses in the industrial lens, the focal length of the industrial lens can be changed within a certain range, so that the CCD industrial camera can obtain both panoramic images and partial detailed images without changing the industrial lens. The range of zoom industrial lens generally has 6, 8, 10, 12, 16, 20, 50 times and other grades. To 2. Variable aperture industrial lens The industrial lens is equipped with a variable aperture that can control the amount of light input, so that the relative aperture F of the industrial lens can be continuously changed, so as to adapt to the correct exposure of objects with different brightness. It has been mentioned that adjusting the size of the aperture can affect the length of the depth of field. Therefore, in order to obtain the effect of large depth of field, if the lighting permits, the intensity of the illumination should be increased as much as possible, and the aperture should be reduced to obtain a larger depth of field. According to the function classification, it can be further divided into automatic focusing industrial lens, automatic iris industrial lens and so on.