Carriage Mechanism; Cr Motor Specifications; Cr Variation Measurement Sequence; Cr Measurement Sequence - Epson Stylus Photo R1800 Service Manual

EPSON Stylus Photo R1800/R2400

2.2.1 Carriage Mechanism

The Carriage mechanism consists of the Carriage Motor (CR Motor), Carriage
Shafts, Platen Gap Adjustment Mechanism, Carriage Lock Mechanism, and
others.
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 machanism 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 (A6<H>). 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)
29.2Ω ± 10%
30.0mH ± 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 A4<H>, A5<H> at power-on or after
replacement of the Ink Cartridge (s). However, if 6E is saved at the
EEPROM A4<H> and 05 at A5<H>, Fatal error will occur since too large
load is applied to the CR drive system.
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
motor and like. 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
17