In recent years, with the development of information system products, the types of display devices utilized are becoming more sophisticated and complicated.
Displays of earlier stages are now being replaced by 5×7 dot type displays which allow the display of functional symbols as well as alphanumerics.
The dot type display is being developed into a dot matrix type as a more sophisticated product, in the latest stage. A great feature of the dot matrix type display is that it allows display not only of numerals, the alphabet, and other functional symbols but also of graphic features.