Apg (Auto Pg) Mechanism; Apg Motor Specifications - Epson Stylus Photo R1800 Service Manual

EPSON Stylus Photo R1800/R2400
PW sensor dark voltage (VH) measurement
PW sensor dark voltage (VH) measurement is performed at the following
timings and locations and used to calculate the threshold value of whether
paper is present or not.
Cut sheets, Roll paper
The dark voltage is measured and updated at every power-on, and the
threshold value (VS) is calculated and saved in the EPROM area as a
PW detection level.
•
Threshold value detection voltage: Paper present
•
Threshold value detection voltage: Paper absent
CD-R Tray
When printing on a CD-R, the dark voltage is measured on the CD-R
tray, and the threshold value (VS) is then calculated and saved in the
EPROM area as a PW detection level.
•
Threshold value detection voltage: CD-R present
The measurement voltage in the presence of the CD-R is saved into
the EEPROM as a white level. The white level value is used to check
the sensor deterioration condition during servicing or like.
• If the measurement value of the white level is close to that of the PW
detection level, it means that the sensor is dirty or deteriorated.
Operating Principles
(tray home position detected)
Printer Mechanism

2.2.1.4 APG (Auto PG) Mechanism

The following indicates the specification of the DC motor that drives the APG.
Table 2-3. APG Motor Specifications
Item
Type
Drive voltage
Armature resistance
Inductance
Drive method
Drive IC
The APG Motor (DC Motor) and two APG Sensors drive the PG Cam to
automatically adjust the PG amount according to the paper.
APG
Sensor
APG Sensor PG Cam
APG Motor
Figure 2-2. APG Mechanism
Revision B
Specifications
DC motor with brushes
+42V ± 5% (voltage applied to driver)
64.7Ω ± 15%
37.6mH ± 25%
PWM, constant-current chopping
A6628
Carriage Shaft Carriage Unit
19