PURPOSE: To generate pattern information which provides display and output images of the same size even if resolution is altered by providing a means which converts pattern information in response to resolution information and the resolution of pattern information stored in a pattern information storing means.

CONSTITUTION: A pattern memory 29 stores pattern information of prescribed resolution in response to its code information. When resolution information is input from a host computer 10, pattern conversion corresponding to the resolution is carried out based on the pattern information stored in the pattern memory 29, and is stored in a line pattern part 25. Thus, pattern information that provides display and output images of the same size even if resolution is altered can be generated.