Ribbon Feed Mechanism - Epson DFX-8000 Service Manual

2.1.4 Ribbon Feed Mechanism

The ink ribbon is an endless loop. The ribbon feed mechanism takes up the ribbon, and is driven by
the ribbon motor.
Figure 2-5 shows the ribbon feed mechanism operation. The ribbon is fed in one direction only. The
rotation of the ribbon motor (counterclockwise) is transmitted to the ribbon feed gear (clockwise)
through the ribbon feed select gear and ribbon feed transmission gear. The tip of the ribbon feed gear
engages the ribbon cartridge take-up roller to feed the ribbon.
The ribbon motor supplies mechanical power to both the ribbon feed mechanism and tractor select
mechanism. As the ribbon motor pinion rotates, the ribbon feed select gear swings like a pendulum,
using the lever axis as a fulcrum, and the rotation of the motor is transmitted to either mechanism when
the gears are engaged. When the ribbon motor rotates counterclockwise, the rotation of the motor is
transmitted to the ribbon feed mechanism, and when it rotates clockwise, it is transmitted to the tractor
select mechanism.
Ribbon
Motor
Type
Supply voltage
Winding resistance
Drive freauencv
Excitation svstem
Select Gear
Figure 2-5. Ribbon Feed Mechanism Operation
Table 2-5. Ribbon Motor Specifications
4-phase 48-poIe PM-type stepping motor
36.5 & 1 VDC
150 t 10 ohms/phase (at 25"C)
7 2 0
Ribbon
Feed Transmission Gear
2-7
Roller
Ribbon Cartridge
Feed Gear