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 |