Feed for thermal printing ribbon

A method of printing using a thermal print head selectively operable to transfer ink from a thermal transfer inked ribbon to the surface of an item in which the ribbon is made available a plurality of times for ink transfer including the steps of feeding a first item together with the inked ribbon past the print head with the first item in ink transfer relationship with the ribbon during which feeding a first length of ribbon is fed in a first direction past the print head;

• selectively operating the print head to transfer ink from the first length of ribbon to the surface of the item to form a print impression on said first item;
• releasing the first item from engagement with the ribbon;
• feeding the ribbon in a second direction opposite to said first direction by an amount related to said first length;
• feeding a second item together with the inked ribbon past the print head with the second item in ink transfer relationship with the ribbon and selectively operating the print head to effect further transfer of ink from at least a part of said first length of ribbon to the second item.

A method of printing using a thermal print head selectively operable to transfer ink from a thermal transfer inked ribbon to the surface of items, the ribbon being made available a plurality of times for ink transfer, including successively performing a group of steps comprising the steps of feeding a first length of the inked ribbon in a first direction;

• feeding an item past the print head;
• feeding a second length of the inked ribbon in a second direction opposite to said first direction in ink transfer relationship with said item during the feeding of said item past the print head, the first and second lengths of said ribbon being of predetermined relationship so that the second length of ribbon in one group of steps includes a part of the second length in a preceding group of steps;
• selectively operating the print head to transfer ink from the second length of the ribbon including transfer of ink from said part of the second length in a preceding group of steps to said item to form a print impression on said item;
• and
• releasing said item from engagement with the ribbon after forming the print impression thereon.

A thermal printing device including:

• a thermal print head
• means to feed an item upon which printing is to be effected past the print head in a first direction;
• first ribbon feed means to feed a thermal transfer inked ribbon in said first direction between the print head and the item and in ink transfer relationship with the item during passage of the item past the print head;
• print control means operable in a printing operation during feeding of the item past the print head to selectively operate the print head to transfer ink from a region of the ribbon to form a print impression on the item;
• second ribbon feed means operable to feed the ribbon in a second direction opposite to said first direction;
• sensing means responsive to feeding of the ribbon in the first direction to generate first signals representing an extent to which the ribbon is fed in the first direction and responsive to feeding of the ribbon in the second direction to generate second signals representing an extent to which the ribbon is fed in the second direction;
• control means responsive to said first signals and operative after completion of formation of the print impression to operate the second ribbon feed means to feed the ribbon in said second direction until said second signals have a predetermined relationship to said first signals;
• said first ribbon feed means being effective to feed said region of said ribbon past the print head for ink transfer to a subsequent item in a subsequent printing operation.

A franking machine including a thermal print head operable by print signals;

• means to guide a thermal transfer inked ribbon past the thermal print head;
• feeding means to feed a mail item in a first direction past the thermal print head with the thermal transfer ribbon interposed between the mail item and the print head;
• pressure means actuable to press the mail item toward the print head into ink transfer relationship with the ribbon, said engagement being effective to feed the ribbon with the mail item in the first direction;
• rewind means operable to feed the ribbon in a second direction opposite to said first direction;
• control means operable to actuate the pressure means and to generate print signals to operate the print head to cause transfer of ink from the ribbon to the mail item to form a franking impression on the mail item during feeding of the mail item together with a first length of ribbon past the print head;
• said control means being operative after completion of formation of the franking impression to terminate actuation of the pressure means to release the ribbon;
• sensor means operative to generate first signals representing a first length of ribbon fed with the mail item in said first direction and second signals representing a second length of ribbon fed in said second direction by said rewind means;
• and said control means being responsive to said first and second signals and operative to control operation of the rewind means to feed the ribbon in the second direction until the second signals have a predetermined relationship with said first signals.