PRINTER FOR DUPLEX TYPE COPYING PAPER

PURPOSE:To carry out printing on a sheet of duplex type copying paper of different kinds with one printer. CONSTITUTION:A printer comprises feed rollers 2, 3, 4 for feeding duplex type copying paper, photo sensors 12, 13, 14 for detecting the length and width of a paper sheet 1, a printing head 15 for printing on the sheet 1, actuators 9, 17 for the feed rollers and the printing head, and control means 20. The sheet length is measured by the driving pulse number of a stepping motor 10 in the actuator 9 which is counted during the detection of the sheet l by the photo sensors 12, 13, 14, and, at the same time, the sheet width is determined from the number of the photo sensors emitting signals. The kind of the sheet 1 is found by the comparison between the obtained data on the sheet 1 and the data on standard profiles stored in the control means 20, and, simultaneously, a format of a printing range in the sheet 1, which is stored in the control means 20, is called to carry out printing on the basis of the format.