Platen Gap (Pg) Adjust Mechanism; Paper Feeding Mechanism - Epson Stylus COLOR 760 Service Manual

EPSON Stylus COLOR 760

2.1.1.4 Platen Gap (PG) Adjust Mechanism

The PG adjustment, at the right of the printer mechanism, consists of the PG
lever, PG support lever, right/left parallelism adjustment levers, and CR guide
shaft.
The PG adjustment mechanism is designed to keep the platen gap correct for
the paper thickness to prevent ink from smearing. The PG support lever joins
the CR guide shaft, which has and eccentricity via PG support lever. Switching
the lever from "0" to "+" rotates the CR shaft and changes the platen gap from
narrow to wide.
Table 2-3.
Platen Gap Adjust Lever Setting
Paper Lever Position
All Media Front
If you find any print
problems or you Rear
use thick paper
Operating Principles
PG adjustment value
0 mm
(1.14mm between head and platen)
0.7mm
(1.84mm between head and platen)

2.1.1.5 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 for the PF
motor. See the table below for the DC motor specifications.
Table 2-4.
Item
Motor type
Drive voltage
Coil Resistance
Drive frequency [Hz]
Control method
Unlike a stepping motor, the DC motor that drives the paper feeding
mechanism can not measure the paper feeding amount by referring to the
pulses given. For this reason, the loop scale and encoder sensor are directly
attached to the left end of the PF roller shaft to mechanically control paper feed
amount. See Section 2.2 for detailed information on the PF motor control
circuit.
Drive from the PF motor is sent to the PF rollers and paper eject rollers as
described below.
o
To the PF rollers:
PF motor pinion gear (CCW rotation)
o
To the eject rollers:
PF motor pinion gear (CCW rotation)
(13.5, 308) Spur gear (28)
NOTE: Above CCW rotation is mentioned viewing from the PF motor pinion gear
side.
Figure 2-6 in the next page gives the paper feeding mechanism block diagram,
showing the parts along the PF motor drive transmission paths.
Overview
PF Motor Specifications
Description
DC Motor with Brush
+42V +/- 5% (DRV IC voltage)
31.1 ohm +/- 25%
26.6mH +/- 25%
A3958
Spur gear (76) PF rollers
Spur gear (76) Combination gear
Paper eject rollers
Revision C
32