The key of thermal printing technology is the heating element. There is a row of micro semiconductor elements on thermal printer mechanism. These elements are queued in very density, ranging from 200DPI to 600DPI. These elements quickly generate high temperatures when powered by certain current. When the coating of thermal paper encounters the heating elements, temperature rise in a very short time. And then the coating on thermal paper will react chemically and color become visible.

When the thermal printer receives print data, it converts the data into bitmap data. And then it prints out contents on thermal paper by controlling the heating element generated from current, as well as dots of the bitmap data.

Different Sizes of Heating Element