Platen Gap (Pg) /Parallelism Adjustment Mechanism; Carriage Home Position (Hp) Detection; Paper Feeding Mechanism - Epson Stylus PHOTO 2000P Service Manual

EPSON Stylus PHOTO 2000P

2.1.4.2 Platen Gap (PG) /Parallelism Adjustment Mechanism

The PG adjust lever is attached to the left end of the carriage guide shaft.
When the carriage guide shaft, which has an eccentricity, rotates as the
adjustment lever moves, it narrows or widens the distance (=PG: from 1.2
mm to 2.1 mm). This mechanism enables the user to print with a correct
PG according to print result or other conditions such as paper curl.
Also, the parallelism adjustment bushings are attached to the right and
left ends of the carriage guide shaft. They are used to set the carriage
guide shaft parallel with a platen.
Table 2-8.
Platen Gap Adjust Lever Setting
Table 2-9.
Lever Position
Front (0)
Rear (+)

2.1.4.3 Carriage Home Position (HP) Detection

Unlike previous Epson ink jet printers, the carriage home position is
detected with the drive current from the CR motor and speed/position
signal from the linear encoder.
OPERATING PRINCIPLES
PG adjustment value
0 mm (=PG is 1.2 mm)
+ 0.9 mm (=PG is 2.1 mm)

2.1.5 Paper Feeding Mechanism

The paper feeding mechanism transports paper loaded from ASF using
the PF rollers and paper eject rollers. A new type of DC motor is used as
the PF motor. See the table below for the PF motor specifications.
Table 2-10.
Item
Motor type
Drive voltage
Coil Resistance
Inductance
Control method
Stepping motor that is used in other printers as the PF motor controls
paper feed by the open loop system. On the other hand, this printer
controls paper feeding mechanism with the closed loop system by
employing the DC motor and rotary encoder for more accurate paper
feeding. Therefore, a rotary encoder attached to the left end of the PR
roller shaft controls paper feed amount. For detailed information, see
Section "PF motor driver circuit".
Drive from the PF motor is sent to the PF rollers and paper eject rollers as
described below.
Drive transmission to the PF rollers:
PF motor pinion gear
Drive transmission to the eject rollers:
PF motor pinion gear
→ →
Spur gear (28) Paper eject rollers
Overview
PF Motor Specifications
Table 2-11.
Description
DC Motor with Brush
+42V +/- 5% (Applied to the driver)
31.1 ohm +/- 25%
26.6mH +/- 25%
Constant current chopping drive
→ →
Spur gear (76) PF rollers
→ →
Spur gear (76) Combination gear (13.5, 308)
Revision A
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