Carriage (Cr) Mechanism - Epson Stylus COLOR 800 Service Manual

EPSON Stylus &2/25 800

2.2.3 Carriage (CR) Mechanism

The CR mechanism is composed of the CR motor, Timing Belt, CR Guide Shaft, Top Frame, and Home
Position (HP) sensor. The torque from the CR motor is transmitted to the CR unit via the Timing Belt to
move the CR unit along the CR Guide Shaft both right and left, depending on the direction in which the CR
motor rotates. When the CR unit returns to the HP position, it is detected by the HP sensor mounted on
the right end of the Top Frame, and the information is fed back to the IC2 gate array (E05B33CB). Figure
2-4 illustrates the CR mechanism conception.
The CR motor, which drives the CR mechanism, is a 4-phases/200-pole/HB type stepping motor and is
controlled by the constant current bipolar control system. The current control signal for each phase and
phase control signal output from the IC2 gate array E05B33CB are converted into the CR motor control
signal by the IC13 bipolar driver UDN2917EB to control the CR motor. Refer to Table 2-2 and Table 2-3
which show the CR specification and the drive frequency.
Item
Motor type
Drive voltage
Coil resistance
Inductance
Drive frequency
Excitation mode
Minimum step
Mode CR speed
(CPS)
Fast skip 340
DRAFT 266.7
LQ 200
TEXT LQ 200
SLQ 100
Capping 90
wiping 2 80
Wiping 40
Capping 20
(open)
Constant 20
value
Note) *1: Step : reduced to 2-2 phase
*2: Acceleration
*3: Deceleration
2-4
Figure 2-4. Carriage Mechanism
Table 2-2. CR Motor Specification
4-phases / 200-pole / HB type stepping motor
42 VDC 5%
7.8 10% (at 25 C per 1 phase)
14 mH 20% (1 KHz, 1 Vrms)
240 ~ 4080 Hz
Bipolar drive
1/120 inch / pulse (2-2 phase drive), 1/240 inch / pulse (1-2 phase
drive)
1-480 inch / pulse (W1-2 phase drive)
Table 2-3. CR Motor Drive Terms
Drive Drive system and acceleration/deceleration
frequency
2 3
(Hz) A* :1, D*
4080 64 (W1-2)
3200 88 (W1-2)
2400 432 (W1-2)
2400 240 (W1-2)
1200 432 (W1-2)
1080 64 (W1-2)
960 64 (W1-2)
480 16 (W1-2)
240 8 (W1-2)
240
Description
step
:2 A:2, D:2
164 (2-2)
86 (2-2)
Acceleration/
De celeration
Constant pulse*
(2-2) 180
(2-2) 108
(W1-2) 108
(W1-2) 60
(W1-2) 108
(W1-2) 16
(W1-2) 16
(W1-2)
(W1-2)
(W1-2)
1
4
2
Rev. A