The principle of thermal printer is to coat a transparent film on a light-colored material (usually paper). After heating for a period of time, the film will turn black (usually black and blue). The image is produced by heating to produce a chemical reaction in the film. This chemical reaction is carried out at a certain temperature.
High temperature will accelerate this chemical reaction. When the temperature is lower than 60℃, it takes a long time for the film to turn black, even several years. When the temperature is 200℃, the reaction will be completed in a few microseconds. The thermal printer selectively heats the thermal paper at some positions, thus producing corresponding graphics.
Heating is provided by a small electronic heater on the print head in contact with heat-sensitive materials. The heater is logically controlled by the printer in the form of square dots or strips. When driven, a pattern corresponding to the heating element is generated on the thermal paper. The same logic circuit that controls the heating element also controls paper feeding, so that graphics can be printed on the entire label or paper.
The most common thermal printers use a fixed print head with a heating grid. The print head has 320 square dots, and the size of each dot is 0.25mm×0.25mm With this lattice, the printer can print the dots at any position on the thermal paper. This technology has been applied to paper printers and label printers.
App application
Thermal printers are quieter and faster than dot printers. They are smaller, lighter and consume less power, making them very suitable for portable and retail applications. Its efficiency can be used in retail industry.
Network-based printers can be quickly replenished. Commercial applications of thermal printers include gas station pumps, kiosks, point-of-sale systems, slot machines in coupon printers, label transportation and print on demand products, as well as recording real-time heart rhythm bands of heart monitors in hospitals.
Early formulations of thermal coatings used in thermal paper were sensitive to accidental heat, abrasion, friction (which would cause heat and thus darken the paper), light (which would fade the printed image) and water. The later thermal coating formula is more stable; In practice, hot stamping text should be kept clear for at least 50 days.
In many hospitals in Britain, many common ultrasonic waves? Ultrasound equipment outputs the scanning results to thermal paper. If parents want to save images by laminating, this may cause problems, because the heat of most laminators will darken the whole page-this can be pre-tested on unimportant thermal prints. One option is to make and laminate a permanent ink copy of the image.
Refer to the above? Baidu encyclopedia-thermal printer