How thermal printers work
The working principle of a thermal printer is that a semiconductor heating element is installed on the print head. After the heating element is heated and contacts the thermal printing paper, the corresponding graphics and text can be printed. The pictures and texts are generated by the chemical reaction of the coating on the thermal paper by the heating of the semiconductor heating element. This chemical reaction is carried out at a certain temperature. High temperatures accelerate this chemical reaction. When the temperature is lower than 60°C, the thermal printing paper takes quite a long time, even several years, to turn dark; when the temperature is 200°C, this chemical reaction will be completed within a few microseconds.
The thermal printer selectively heats the thermal paper at a certain position, thereby producing the corresponding graphics. Heating is provided by a small electronic heater on the printhead that is in contact with the heat-sensitive material. The heaters are logically controlled by the printer in the form of square dots or strips. When driven, a graphic corresponding to the heating element is generated on the thermal paper. The same logic that controls the heating element also controls the paper feed, allowing graphics to be printed on the entire label or sheet.
The most common thermal printer uses a fixed print head with a heated dot matrix. Using this dot matrix, the printer can print on the corresponding position of the thermal paper.
Application of thermal printer
Thermal printing technology was first used in fax machines. Its basic principle is to convert the data received by the printer into dot matrix signals to control the heating of the thermal unit, and to heat and develop the thermal coating on the thermal paper. At present, thermal printers have been widely used in POS terminal systems, banking systems, medical instruments and other fields.
Classification of thermal printers
Thermal printers can be divided into line thermal (Thermal Line Dot System) and column thermal (Thermal Serial Dot System) according to the arrangement of their thermal elements. Column-type thermal is an early product. Currently, it is mainly used in some occasions that do not require high printing speed. Domestic authors have already used it in their products. Line thermal is a technology in the 1990s, and its printing speed is much faster than column thermal, and the current fastest speed has reached 400mm/sec. To achieve high-speed thermal printing, in addition to selecting a high-speed thermal print head, there must also be a corresponding circuit board to cooperate with it.
Advantages and disadvantages of thermal printers
Compared with dot matrix printers, thermal printing has the advantages of fast printing speed, low noise, clear printing and convenient use. However, thermal printers cannot directly print double sheets, and the printed documents cannot be stored permanently. If the best thermal paper is used, it can be stored for ten years. Dot-type printing can print duplexes, and if a good ribbon is used, the printed documents can be stored for a long time, but the printing speed of the needle-type printer is slow, the noise is large, the printing is rough, and the ink ribbon needs to be replaced frequently. If the user needs to print an invoice, it is recommended to use a dot matrix printer, and when printing other documents, it is recommended to use a thermal printer.
Post time: Apr-08-2022