Printer with interchangeable printing heads

Printer with interchangeable printing heads for printing documents, comprising:

• a carriage for interchangeably holding one of an ink jet printing head having a plurality of ink ejecting nozzles and a frame supporting a wire printing head having a plurality of printing needles and moving said ink jet printing head or said frame in a forward direction and in a backward direction along a print line;
• a fixing device for removably fixing said ink jet printing head or said frame supporting said wire printing head to said carriage;
• sensing means for sensing the presence on said carriage of said ink jet printing head and of said wire printing head;
• and,
• a control device, responsive to said sensing means, for controlling the operation of said ink jet printing head and said wire printing head, said control device comprising activatable first driving means for driving said ink jet printing head and second driving means for driving said wire printing head, said first driving means being activated for supplying pulses of low current intensity to said ink jet printing head when said sensing means sense the presence on said carriage of said ink jet printing head, and said second driving means being activated for supplying pulses of medium current intensity to said ink jet printing head when said sensing means sense the presence on said carriage of said wire printing head, whereby single copy or multiple copies documents are printed;
• wherein said frame also supports a removable cartridge for an ink ribbon, said ink ribbon being operatively associated with said plurality of printing needles in order to transfer ink from said ink ribbon to said documents, whereby the removal of said wire prim head from said carriage causes the simultaneous removal of said ink ribbon cartridge.