3-4
3.3 PAPER FEED CHARACTERISTICS
!
Paper is fed in a forward direction when the motor shaft is rotating in the normal direction
(anticlockwise) when seen from the motor gear side.
!
The motor is driven by a 2-2 phase excitation, constant current chopper method and feeds
paper 0.0625 mm (equivalent to 0.5 dot pitch) every one step of the motor drive signal.
!
To prevent deterioration in printing quality due to backlash of the paper feed system, the motor
should be rotated 20 steps anticlockwise (the backlash absorption step should be input) when
seen from the motor gear side, after initialization, after opening or closing the platen block, or
after cutting thermal paper with the autocutter or tear bar (hand cutter). Be sure to start printing
after such operation.
!
During paper feeding, the motor should be driven lower than the value obtained by equation (1)
and (2).
Equation (1):
Vp > 5.5 V
Vp
×
160 + 80 (pps)
(Max. 1440 (pps))
Equation (2):
Vp
≤
5.5 V
Vp
×
210 - 195 (pps)
!
During printing, the 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
.)
!
Do not rotate the motor anticlockwise when seen from the motor gear side.
Table 3-2 Sample Motor Drive Frequency
Operating
Voltage
Drive Frequency
(Paper feed)
Motor Pulse Width
Feed Speed
4.5 V
750 pps
1333.3 µs
46.9 mm/s
5 V
855 pps
1169.6 µs
53.4 mm/s
6 V
1040 pps
961.5 µs
65 mm/s
7.2 V
1232 pps
811.7 µs
77 mm/s
8 V
1360 pps
735.3 µs
85 mm/s
8.5 V
1440 pps
694.4 µs
90 mm/s
