PURPOSE: To print an emphasized character even by a laser printer or FAX, by providing an emphasizing means for converting the dot pattern of a character font to which a character code having an overlap printing code applied thereto corresponds, to a thick character.

CONSTITUTION: A control part 1 reads the corresponding character font from a character generator 4 with respect to the character code unnecessary for the usual emphasis of a character in inputted printing data and said character font is converted to a serial image signal by a FAX converting circuit 5 to be sent to a telephone circuit through a modem circuit 11. When a character code having an overlap printing code applied thereto is inputted, an MPU 2 converts the dot pattern of the corresponding character font to a thick character to similary transmit the same through the FAX converting circuit 5 and the modem circuit 11. By this method, a thicknened emphasized character can be printed even in a laser printer or FAX without especially preparing for a character generator equipped with an emphasized character font.