Image printing method and system

An image printing system, comprising:

• image signal inputting means for inputting an image signal;
• and
• a printing mechanism which includes:
• a control circuit responsive to inputting of an image signal for outputting a head control signal for controlling printing density based on said image signal and outputting a motor drive signal for controlling transportation of an ink sheet and a printing sheet,
• a thermal head responsive to said head control signal for adjusting heat generating states of heat generating elements,
• drive motor means for generating a driving power for transporting said ink sheet and said printing sheet in response to said motor drive signal, and
• driving mechanism for transporting said ink sheet and said printing sheet by utilizing said driving power generated by said drive motor;
• and
• said printing system further comprising command means for commanding a size of a sheet used for printing, position of an image to be printed and a size of said image;
• wherein said control circuit incorporates a function for determining a transportation quantity for transporting said printing sheet based on said printing sheet size, said image printing position and said image size and determining arithmetically said motor drive signal corresponding to said transportation quantity, a function for discriminatively deciding a printing area where said image is to be printed and a non-printing area where said image is not to be printed based on said printing sheet size, said image printing position and said image size, and a function for determining a printing start timing based on a result of said discriminative decision and said drive motor signal and outputting said head control signal based on said image signal.