PURPOSE: To improve the storage efficiency of character pattern font data having a dot matrix format for storing in a memory medium.

CONSTITUTION: The prescribed blank part of a-bytes on the left side or the right side of each of dot matrix format character patterns ('A', 'B', and 'C') having the capacity of W-bytes per one character is originally considered as a common region with the character patterns adjoining each other. When these character patterns above mentioned are in a character pattern memory medium, they are memorized as (W-a)-bytes per one character pattern.