PURPOSE: To enable a recording operation to be rapidly stopped when an abnormal condition is generated, by diagnosing an abnormal feed of an ink ribbion from a command signal for feeding an ink ribbon and a detection signal of rotation of an ink ribbon payout core.

CONSTITUTION: When a controlling circuit 15 sends an ink ribbion feeding command OP to a motor-driving circuit 14, it also sends a synchronising signal CM synchronized with the command OP to a diagnosing circuit 17. On the other hand, the number of rotations of the payout core 2 rotated by driving a motor 12 is detected by an optical sensor 13 which detects the light reflected from a reflector 7 provided on the lower surface of the core 2, and a payout core rotation detection signal PR is inputted into the circuit 17. The circuit 17 compares the inputted conditions of the signals CM and PR with each other, thereby diagnosing whether or not an abnormal feeding of the ink ribbon 1 is generated. When it is judged that an abnormal feeding has occurred, the circuit 17 outputs a stopping signal RE to the controlling circuit 15, thereby rapidly stopping the recording operation.