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Membrane switch
Touch screen
Flexible circuit
EL backlight
 
Technic
Membrane switch
Touch screen
Flexible circuit
EL backlight
Tel: +86-755--36927705
Fax: +86-755--29530221
Sales: sale@xemda.com.
Support: sale@xemda.com .
 
Technic >> Touch screen    
Touchscreen structure:
Basic principle:
4-Wire resistive touch screen is the preferred solution for low cost applications. It consists of a conductive bottom layer (ITO Glass or Film) and a conductive top layer (ITO Film). The two layers are suspended by many very small spacer dots.When a certain point is touched, the top layer contacts the bottom layer and a voltage charged by the controller is applied to the bottom layer's electrodes. The coordinate X axis of the touch point can be detected by measuring the voltage value thru the top ITO layer and the coordinate Y axis of the touch point can be detected in the same way by changing voltage input to the top layer's electrodes.

The 5 Wire Resistive Touch Screen is a two layer structure,
1. ITO glass substrate with one side uniform resistive ITO coating.
2. A very thick polyester ITO film is tightly suspended over the top of ITO glass substrate. This ITO film has a hard, durable coating on the outer side, on an inner side with ITO coating.
3. The ITO glass and the ITO film is separated by printed small, transparent insulation spacer dots.

When the screen is touched, it pushes the ITO film to have an electrical contact with ITO glass (both on the ITO coating side). It produces a voltage which is the analog representation of the position touched.
No limited to touching medium because it induces by pressure, it can be operated no matter with hand, pencil, credit card, stick...etc. that also can work even though wearing glove

Specification compare:
  4-wire resistive 5-wire resistive
Surface Hardness 3 H 3 H
Optical Clarity
80 % 80 %
Operating Temperature
-10C ~ 60C
-10C ~ 60C
Endurance Test strikes
Over 1 million
Over 1 million
Operating Voltage
5V DC
5V DC
Resistance
200~ 900
30~ 300
Linearity
< 1.5%
< 1.5%
Faceplate Surface
Anti-glare coating
Anti-glare coating
Operation Pressure
15 ~ 70g
15 ~ 70g
Storage Temperature
-20C ~ 70C
-20C ~ 70C
Message Noise
5 m sec ~ 15 m sec
5 m sec ~ 15 m sec
Operating Current
5mA ~ 25mA
5mA ~ 25mA
Isolation Resistance
20M ohm@25V DC
20M ohm @25V DC
Connector Resistance
200 ohm< X Axis <800 ohm
300 ohm< Y Axis <900 ohm
30 ohm< X Axi< 300 ohm
30 ohm< Y Axis <300 ohm
Electrostatic Endurance
No abnormal appearance after 10kv, 100W, 250PF electrostatic used
No abnormal appearance after 10kv, 100W,250PF electrostatic used
Linearity
X- Axis: 1.5%
Y- Axis: 1.5%
X Axis: 1.5%
Y Axis: 1.5%
Operating Voltage
3V ~ 7V DC
3V ~ 12V DC
Operating Current 5mA ~ 25mA 5mA ~ 25mA
Address: Xixiang, Second Industrial Zone Village, Baoan District, Shenzhen, Guangdong China
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