Specifications

3-4
3.3 PAPER FEED CHARACTERISTICS
 Paper is fed in a forward direction when the motor shaft is rotating in the normal direction
(clockwise) when seen from the motor gear side.
 The motor is driven by a 2-2 phase excitation, constant current chopper method and feeds paper
by 0.125 mm (equivalent to a single dot pitch) every two steps of the motor drive signal.
 To prevent deterioration in printing quality due to backlash of the paper feed system, the motor
should be driven 40 steps in a reverse direction then 40 steps in the normal direction during
initialization or following backward feeding.
 During paper feeding, the motor should be driven lower than the value obtained by equation (1).
When at - 5°C or higher:
Equation (1):
Vp × 165 - 220 (pps) (max.1000 (pps) )
When at lower than 5°C:
300 (pps)
 During printing, motor drive frequency should be adjusted according to working conditions such as
voltage, temperature, number of activated dots, etc. (For details, see CHAPTER 5 DRIVE
METHOD.)
 Drive the motor at 200 pps when automatically loading paper, regardless of the voltage.
As for the motor current value, to keep the motor torque, activate the motor by only the first setting
current value (i.e. one current) for the entire motor drive step time. (See Chapter 3.4.3
Precautions for Driving the Motor.)
 It is not possible to print while the motor is rotating in a reverse direction.
Table 3-2 Sample Motor Drive Frequency
Operating
Voltage
Drive Frequency
when feeding paper
Drive Frequency
when automatically
loading paper
4.2 V 473 pps 200 pps
5 V 605 pps 200 pps
6 V 770 pps 200 pps
7.2 V 968 pps 200 pps
8 V 1000 pps 200 pps
8.5 V 1000 pps 200 pps