Epson Stylus Pro 4800 Portrait Edition, Service Manual

Page: 127 / 506

EPSON Stylus Pro 4400/4450/4800/4880/4880C Revision C
Operating Principles Printer Mechanism Components 127
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CR Motor (DC motor)
The Carriage Unit moves left/right by the CR Motor drive. The Encoder
Sensor installed in the Carriage Unit reads (linear encoder system) the slits
of the CR Scale, and this signal is compared to the logic control value by
the Main Board control circuit to perform feedback speed control. The
control maintains high printing speed.
Drive transmission from the CR Motor to the Carriage Unit uses a durable
timing belt that is easy to maintain.
The sensors used in the carriage movement components are described below.
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CR_HP Sensor (Carriage home position)
This is a transmissive photosensor installed at the printer right side.
Insertion of the flag (a protrusion) on the Carriage Unit is detected as the
carriage movement origin (home position). Sensor outputs are "OFF" in the
HP range and "ON" outside the HP range.
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CR Encoder Sensor (Linear encoder)
Installed on the back of the Carriage Unit, this is uses pulse output (2
channels) corresponding to the slit position on the CR Scale for CR Motor
servo control and PTS (Print Timing Signal) formation. The resolution is 1/
180 inch.
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Multi Sensor
This is a reflective sensor installed at the Carriage Unit lower left side, and
it has multiple functions. For details on the Multi Sensor, refer to
"2.2.7
Multi Sensor" (p.145) .
Figure 2-17. Carriage Mechanism Detection Components
CR_HP Sensor
Flag
CR Motor
CR Scale
CR Encoder Sensor
Multi Sensor