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LGE Internal Use Only
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. Technical Brief
3.12.4. Touch Interface
In GM750, 4-wire touch screen panel is used for user input method.
Two resistive layers make up a 4-wire touch screen panel and are separated by
insulating dots. The inside surface of each layer is coated with a transparent metal
oxide coating that generates a gradient across each layer when voltage is applied.
Table. MSM7200A Touch screen connections
Table. Recommended operation conditions
Figure. Touch screen circuit
4 7
4 7
4 7
4 7
3
0
6
D
4
3
5
2
6
1
0
0
1
5
0
6
R
3
0
6
N
C
4
3
2
1
0
0
1
6
0
6
R
0
0
1
7
0
6
R
0
0
1
8
0
6
R
L
X
2
X
_
H
C
U
O
T
R
X
1
X
_
H
C
U
O
T
D
Y
1
Y
_
H
C
U
O
T
U
Y
2
Y
_
H
C
U
O
T
3
0
6
0
0
.
1
.
v
e
R
