COVID-19 can be spread through droplets formed by coughing and breathing, so epidemic monitoring and prevention in public areas has become an important part of containing the epidemic. During the Spring Festival travel, airport hubs, high-speed railway stations, passenger stations and other places have large passenger flow and dense personnel, and the initial inspection of the epidemic situation is of great significance. The symptoms of COVID-19 patients are mainly fever, cough, dyspnea and fatigue, so body temperature screening has become one of the main means of epidemic monitoring in public areas.
Judging from the current research situation, the temperature screening equipment in public areas is mainly non-contact equipment, including mobile screening systems, stationary screening systems, and handheld screening equipment. Compared with traditional contact-type body temperature screening equipment (thermometers, etc.), non-contact-type equipment can monitor the target body's temperature online based on the intensity of infrared rays, so as to achieve efficient and rapid screening of passing people, and the screening efficiency is greatly improved.
Infrared, also known as infrared thermal radiation, has wavelengths between 0.76 and 1,000 microns, and wavelengths between microwaves and visible light. The amount of infrared energy is directly related to the temperature and material properties of the surface of the object. The higher the temperature, the greater the infrared energy.
The infrared screening instrument determines the temperature of the object by the amount of infrared radiation energy emitted by the object.
Simply put, infrared body temperature screening is performed in three steps:
The first step is to use an infrared detector sensitive to infrared radiation to convert the infrared radiation into a weak electrical signal, the size of which can reflect the strength of the infrared radiation;
The second step is to use the subsequent circuit to amplify and process the weak electrical signal, so as to clearly collect the temperature distribution of the target object;
The third step is to process the above-mentioned amplified electrical signals through image processing software to obtain electronic video signals. The television imaging system displays the electronic video signals reflecting the target infrared radiation distribution on the screen to obtain visible images.
The infrared screening system can be decomposed into several parts: chip, detector, movement and the whole machine. The infrared MEMS chip is the core component of the infrared imaging system and is at the top of the entire infrared imaging industry chain. The infrared MEMS chip gathers the infrared light signal collected by the infrared optical system into the detector, and converts the infrared light signal into a weak electrical signal through the IC and MEMS system for output.
The design, production and research and development of infrared detectors involve many disciplines such as materials, integrated circuit design, refrigeration and packaging, and are technically difficult. At present, only a few countries in the world, such as the United States, France, Israel, and China, can master uncooled infrared detectors. Core Technology.
The movement consists of a detector and an image processing circuit with a public algorithm. The working principle of the movement is to process and digitize the weak electrical signal output by the detector, and to process the digitized signal quantitatively by image and temperature. , and finally convert the temperature distribution map of the target object into a video image. The whole machine is a complete system composed of infrared optical system, movement, intelligent processing circuit, battery, casing, display screen, etc.