The role of institutions is to provide a ribbon of color print source, the ribbon is usually installed in a small disk-shaped box, in the printing process, the oki printer ribbon should keep moving around, driven by the drive mechanism, so that the printing wire comparison uniformly strike the entire ribbon at each position, reducing wear and tear on a local, extended ribbon of use. The print head is a key mechanism for forming the dot matrix printer print-shaped, usually by the vertical arrangement of nine print pins (used for Western print) or 24-pin print (used for Chinese print) of two types. The composition of each print needle device as shown