Carriage Mechanism - Epson Stylus Photo 1390 Service Manual

EPSON Stylus Photo 1390/1400/1410

2.2.1 Carriage Mechanism

The Carriage mechanism consists of parts/units such as the Carriage Motor (CR
Motor), Carriage Shafts, Platen Gap Adjustment Mechanism and Carriage Lock
Mechanism.
2.2.1.1 Carriage Mechanism
The following indicates the specifications of the CR motor (DC motor) that drives the
Carriage.
Table 2-2. CR Motor Specifications
Item
Type
Drive voltage
Armature resistance
Inductance
Drive method
Drive IC
Closed loop control based on the CR Motor (DC Motor) and CR Encoder Sensor has
advantages in stabilized print quality and silent operation.
Heat Generation Control
The printer has a mechanism to reduce the variations in the torque constant and
coil resistance of the DC motors, and variations in output voltage of the Power
Supply Board to obtain a designated heating value.
CR Variation Measurement Sequence
The variations mentioned above are measured in a CR variation measurement
sequence when the CR mechanical load is in the initial status and saved into the
EEPROM. According to the saved information, the printer controls the drive
voltage to obtain a designated driving current. This minimizes the unit-to-unit
variation.
OPERATING PRINCIPLES
Specifications
DC motor with brushes
+42V ± 5% (voltage applied to driver)
23.6Ω ± 10%
17.5mH ± 25%
PWM, constant-current chopping
A6628
CR Measurement Sequence
To set the appropriate drive current value according to the CR mechanical load,
the mechanical load is measured in a CR measurement sequence and saved into
the EEPROM at power-on or after replacing the Ink Cartridge(s).
The above control and sequences correct the drive current value of the CR Motor
according to not only the mechanical load but also the variations of the motors. In
addition, the resultant CR drive current value is used to calculate a heating value, and
when the specified heating value is reached, wait time is provided per CR path for
printing.
Printer Mechanism
Revision B
23