Cameras can be divided into digital cameras and analog cameras. Digital camera can convert analog video signals generated by video acquisition equipment into digital signals, and then store them in computer. The video signal captured by the analog camera must be converted into digital mode by a special video capture card and compressed before it can be converted to the computer for use. Digital camera can capture images directly, and then transmit them to the computer through serial port, parallel port or USB interface. The cameras in the computer market are mainly digital cameras, and the digital cameras are mainly USB digital cameras with new data transmission interfaces, and most of them are visible in the market. In addition, there is a product that works with video capture card, but it is not the mainstream. Due to the rapid popularization of personal computers, the overall cost of analog cameras is high, and it can not meet the BSV LCD splicing screen interface. The transmission speed of USB interface is much higher than that of serial port and parallel port, so digital cameras with USB interface are on the market. Analog camera can be used with video capture card or USB video capture card, which is convenient to connect with computer. The typical application is general video surveillance. Clean area camera, clean area embedded special camera is a special camera for real-time monitoring of key positions of important equipment in clean area clean room. The flat panel of the camera is embedded with color steel plate, which has zero sanitary dead angle, convenient cleaning and installation, and can be quickly and multipoint controlled. It is compatible with mainstream video systems. A webcam generally has basic functions such as video shooting/transmission and still image capture. It processes the image by the photosensitive component circuit and control component in the camera and converts it into a digital signal that can be recognized by the computer. Then it is input to the computer through a parallel port or USB connection, and then the image is carried out by software