PRINTER

PURPOSE:To enable a printing format to be automatically set through a simple operation, by providing a carriage part with an optical sensor for reading a printing position mark provided on a printing paper and with a controlling circuit for recognizing and storing a printing position based on a signal from the sensor. CONSTITUTION:A controlling circuit for recognizing and storing a printing position based on a signal from an optical sensor 11 comprises a printing position recognition and storage controlling circuit 12, a control panel 13, a format- reading switch 14 and a printer-controlling circuit 15. A printing paper 10 carrying markings 17 according to a format to be used is set to a printer, and an automatic reading switch 14 is depressed, then the printer sequentially reads and stores the positions of markings provided at each prescribed printing position while feeding the paper 10 and performing carriage scanning. Thereafter, printing data partitioned on the basis of each prescribed printing position are transferred from a system to the printer and printing is performed according to the printing format stored in the printer.