Epson LQ 300 - Ribbon Advance Mechanism

LQ-300 Service Manual
Operating Principles
2.1.4 Ribbon Advance Mechanism
The ribbon is held between the ribbon advance roller (ribbon driven gear) and the ribbon pressure
roIler. When the carriage moves on the CR guide shaft from left to right and vice versa, the timing
belt turns the belt driven pulley. Then the torque is transmitted to the ribbon driving gear through
the gear trains. The ribbon driving gear rotates counterclockwise no matter what direction the
carriage moves, because a planetary gear is used in the gear linkage.
Table 2-3. Ribbon Advance Gear Linkage
) I 1
Direction of Carriage Movement
Gear Linkage
Left to right
Belt driven pulley + Gear(1)+ Gear (2) -+
(indicated by the black arrow)
Ribbon driving gear
Right to light
Belt driven pulley
+ Gear(1)+ Gear (3)+
irtdioated by the white arrow)
Gear (4) + Ribbon driving gear
The ribbon brake spring, attached to the exit of the cartridge case, prevents slack in the ribbon and
keeps the ribbon tension at an appropriate level.
The ribbon mask prevents the ribbon from
brushing against the paper.
Ribbon Advance Roller
\ &
Ink Ribbon
Ribbon
Pressure
/
Mask
R
Ribbon Brake
D
Carriage
Figure 2-8. Ribbon Advance Gear Linkage
Spring
Rev.A
2-7