Epson Stylus Photo 1390 - 2.2.1.4 APG (Auto Platen Gap) Adjustment Mechanism

EPSON Stylus Photo 1390/1400/1410 Revision B
OPERATING PRINCIPLES Printer Mechanism 25
 Detection of CD/DVD Tray Control
(The Stylus Photo 1390 is not equipped with CD/DVD related units.)
Before starting to print, determines the type of media.
 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.
 CD/DVD Tray
(The Stylus Photo 1390 is not equipped with CD/DVD related units.)
When printing on a CD-R, the dark voltage is measured on the CD/DVD tray,
and the threshold value (VS) is then calculated and saved in the EEPROM
area as a PW detection level.
• Threshold value detection voltage: CD-R present
(tray home position detected)
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 on occasions such as servicing.
• 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.
2.2.1.4 APG (Auto Platen Gap) Adjustment Mechanism
The following indicates the specification of the DC motor that drives the APG adjuster.
The APG Motor (DC Motor) and two APG Sensors drive the PG Cam to automatically
adjust the PG amount according to the paper.
Figure 2-2. APG Mechanism
Table 2-3. APG Motor Specifications
Item Specifications
Type DC motor with brushes
Drive voltage +42V ± 5% (voltage applied to driver)
Armature resistance 64.7Ω ± 15%
Inductance 37.6mH ± 25%
Rotor Inertia 3.94gcm
2
Drive method PWM, constant-current chopping
Drive IC A6628
Carriage Shaft
Carriage Unit
APG Motor
PG CamAPG Sensor
APG
Sensor