AUTOMATIC CERTIFICATE ISSUING MACHINE

PROBLEM TO BE SOLVED: To specify which kind of certificate is issued, or when and to whom the certificate is issued by changing image data described in the certificate for each kind of the certificate or each time the certificate is issued. SOLUTION: A laser printer 120 prints image data according to a printing signal transmitted based on a change pattern from a main CPU 100 which reads a dot pattern data change table stored in an HDD 101 according to a bit pattern corresponding to it. For example, black dots in plural dots are changed to white dots, or white dots are changed to black dots. This dot array can be set in the change pattern table as a certificate to be issued to, for example, specific Mr. A. Then, when the Mr A performs the issuing operation of a certificate by an automatic certificate issuing machine, the dot array corresponding to the Mr. A is read from the change pattern, and the image data corresponding to the dot array are printed on the certificate.