Epson Stylus Pro 9000 - Carriage

EPSON Stylus Pro 9000 Revision B
Operating Principles Description of Components 38
CARRIAGE
Unlike previous models, the SP 9000 uses a special system to ensure the
distance between the printhead nozzles and paper remains the same for all
supported paper types. The carriage (main) attaches to the CR Guide Rail
using bearings, and the carriage (main) contains the subcarriage. The
subcarriage holds the ink cavities, printheads, and so on.
Figure 2-6. Carriage Mechanism & CR Guide Rail (side view)
The subcarriage can be moved using the PG Cam which is driven by the PG
Gears, causing the subcarriage and all its components to move slightly up or
down. The position depends on the thickness of the paper. The position
changes because the PG Cam is somewhat oval shaped and off-centered, so
one side pushes the subcarriage up further than the other side.
The printheads are the same type used in the EPSON Stylus Pro 5000, and
are installed in the same way. Therefore, when installing or replacing the
printheads, make sure neither head leans one way or the other, and make sure
the nozzles of both printheads are exactly lined up vertically. To adjust the
heads, separate adjust levers are provided.
Other sensors and components attached to or related to the carriage are:
 P-EDGE sensor
This sensor measures the distance between the right and left edges of the
paper. The light emitted from the sensor is reflected back to the sensor
where paper exists. In this way the sensor determines where the paper’s
edge is and how wide the paper is.
 PG origin sensor
This sensor detects when the subcarriage is in the thick paper position or
normal paper position. The PG Gear rotates with the PG Cam, and the PG
origin sensor uses a light-reflecting sensor to determine (according to the
hole in the PG Gear) the current subcarriage position, thick paper or
normal paper.
Be aware that the PG Cam and the PG Gear (hole) must
line up properly for the platen gap adjustment operation
to work properly. The Can and Gear are lined up
properly if when the flattest side of the Cam faces the
Lower Paper Guide, the hole of the Gear faces the CR
steel directly above.
Carriage
CR Guide Rail
(frame span)
Printhead
PG Cam
PG Gear
Bearings
Subcarriage
(printhead slots)