Epson Stylus Pro 5000, Service Manual, Page: 57 / 780

Stylus Pro5000 Chapter2 Operating Principles
Rev.A
2-18
2.1.1.11 PG Disengage Mechanism
Stylus Pro 5000 performs automatic control to change the platen gap, which
the users were controlling the platen gap manually in the previous models.
Usually, the printer perform this operation automatically, according to the
paper type setting from the driver.
PF Motor
(CW)
PF Motor
(CCW)
Transmission Gear
Clutch Roller
PG Driven Gear
Flag for colliding with
carriage
Figure 2-20. PG Changes
[Explaining the operation]
When the printing command is input in the conditions that plain paper or
Photo Quality Ink Jet paper (landscape) is selected on the driver, or the
media type lever is set to Thick Paper, or manual feed thick paper mode is
selected by the alternative function on the control panel, the carriage lets the
flag, which is waiting at the most left edge with the paper width sensor,
collide with the protrusions on the carriage. Once the flag collides with the
carriage, although the positions of the transmission gear and PG driven gear
match as it is shown in the figure 2-20, they can not be really engaged with
each other, since there is still gap between them. Therefore, the whole
transmission gear falls into the PG driven gear side by rotating the PF motor
counterclockwise, then, the PG driven gear rotates. The figure 2-21 shows
the condition of small(narrow) platen gap before the PG driven gear rotates,
and figure2-22 shows the condition of the gear train after the PG gap
becomes wider.
Carriage Guide Axis(Rear)
Carriage Guide Axis(Front)
PG Driven Gear Powder Coated Roller
Driving Gear
(High precision gear)
Clutch gear by statical friction
torque
Figure 2-21. Gear Train Condition when PG is narrow(small)