As the hardware foundation of office automation system, office equipment has a very broad development prospect, mainly composed of printers, copiers, fax machines, projectors, paper shredders, and attendance machines. The application environment of equipment in this field is mainly office environments, which do not require high temperature and humidity, but have relatively high requirements for stability, and must meet certain requirements for anti-power interference. The main applications are 2.8 inches, 3.5 inches, 4.3 inches, and 5 inches. 7 inches, etc., the installation method is mainly external installation.