To execute high-quality printing by using an ink sheet set to a printer while surely preventing use of an imitation ink sheet.
The ink sheet 25 is stored in an ink sheet cassette. An ink sheet cassette side identification code is provided to the ink sheet cassette. A sensor reads the ink sheet cassette side identification code. An identification code 28 on the ink sheet 25 side is expressed by a combination of the presence or the absence of a margin formed to one side part S of respective ink areas 30-33 while making the respective ink areas 30-33 as one set. A code reading sensor 40 reads the identification code 28. Printing is allowed when the ink sheet cassette side identification code and the identification code 28 correspond to each other. Printing is regulated when both codes do not correspond to each other.
KATSUMA NOBUO
NISHINO NAOYUKI
HAYASHI JUNJI
MIYAJI KAZUO
Shigeru Iijima
Kobayashi Hideyoshi