Epson Stylus Color, Service Manual

Page: 45 / 151

EPSON Stylus Photo
Rev. A
2-8
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 Phase B
Phase a 10a l1a Current
Duty
Phase b 10b l1b Current
Duty
0 0 1 0 +2/3 0 1 0 +2/3
1 0 0 1 +1/3 0 0 0 +1
2 X 1 1 0 0 0 0 +1
3 1 0 1 -1/3 0 0 0 +1
4 1 1 0 -2/3 0 1 0 +2/3
5 1 0 0 -1 X 0 1 +1/3
6 1 0 0 -1 1 1 1 0
7 1 0 0 -1 1 0 1 -1/3
8 1 1 0 -2/3 1 1 0 -2/3
9 1 0 1 -1/3 1 0 0 -1
10 X 1 1 0 1 0 0 -1
11 0 0 1 +1/3 1 0 0 -1
12 0 1 0 +2/3 1 1 0 -2/3
13 0 0 0 +1 1 0 1 -1/3
14 0 0 0 +1 X 1 1 0
15 0 0 0 +1 0 0 1 +2/3
This W1-2 phase drive (or 2W1-2 phase drive) is called Micro-step and is attached with so called
2/3
•E
Vref or 1/3
•E
Vref 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.
Carriage proceeding
direction
Rotation direction of
Rotor 1*
Drive method Proceeding order of
sequence
HP
→
80 column direction Clockwise direction
2-2, 1-2, W1-2 phase
Sequence No.0
→
15
80 column
→
HP direction Counterclockwise
direction
2-2, 1-2, W1-2 phase
Sequence No.15
→
0
Note)
1* Looking from rotor shaft side.
Table 2-4.Motor Drive Sequence(W1-2.phase drive)
Table 2-5. Relationship Between Rotation Direction and Carriage Operation