Epson Stylus Photo Service Manual page 45

EPSON Stylus Photo
The table below shows W1-2 phase drive sequence at each steps when the rotor of carriage motor
makes one rotation. In the EPSON Stylus Photo, in addition to a function that printing is performed with
W1-2 drive phase, high speed skip mode which is a function to skip over the blank from the end of the
printing data to the next data starting point in high speed, can be also performed by 2-2 and 1-2 phase
drive. W1-2 phase requires 4 times as much steps as 2-2 phase drive, calculating 2-2 phase as standard.
By using this method, it becomes possible to supply constant and stable torque to the motor. As a result, it
also becomes difficult to be influenced by vibration from the printer mechanism during printing.
Sequence
Number
Phase a
0 0
1 0
2 X
3 1
4 1
5 1
6 1
7 1
8 1
9 1
10 X
11 0
12 0
13 0
14 0
15 0
This W1-2 phase drive (or 2W1-2 phase drive) is called Micro-step and is attached with so called
2/3•EVref or 1/3•EVref factor, compared with drive current value (Vref100%) which is supplied at 2-
2phase drive. This Micro-Step allows the rotor to have delicate rotation. In the 2-2 phase drive method, it
is usually
required to take 4-step sequence in order to rotate the rotor once. However, in case of W1-2 phase,
it is required to take 16-step sequence(in the table 2-4, sequence 0•`15) which is 4 times more than
2-2 phase method to do that. Also, in case of 2W1-2 phase drive which can be seen in the Stylus Color
etc., it takes 2-step to rotate the rotor once. The table below shows relation of rotation direction of the rotor
and carriage proceeding direction.
Table 2-5. Relationship Between Rotation Direction and Carriage Operation
Carriage proceeding
direction
HP 80 column direction Clockwise direction
80 column HP direction Counterclockwise
Note) 1* Looking from rotor shaft side.
2-8
Table 2-4.Motor Drive Sequence(W1-2.phase drive)
Phase A
10a l1a
1 0
0 1
1 1
0 1
1 0
0 0
0 0
0 0
1 0
0 1
1 1
0 1
1 0
0 0
0 0
0 0
Rotation direction of
Rotor 1*
direction
Current Phase b
Duty
+2/3 0
+1/3 0
0 0
-1/3 0
-2/3 0
-1 X
-1 1
-1 1
-2/3 1
-1/3 1
0 1
+1/3 1
+2/3 1
+1 1
+1 X
+1 0
Drive method
2-2, 1-2, W1-2 phase
2-2, 1-2, W1-2 phase
Phase B
10b l1b Current
Duty
1 0
0 0
0 0
0 0
1 0
0 1
1 1
0 1
1 0
0 0
0 0
0 0
1 0
0 1
1 1
0 1
Proceeding order of
sequence
Sequence No.0 15
Sequence No.15 0
+2/3
+1
+1
+1
+2/3
+1/3
0
-1/3
-2/3
-1
-1
-1
-2/3
-1/3
0
+2/3
Rev. A