How does a resistive single touch screen detect touched points?

1. Detection Mechanism of 4wire resistive touch screen

As described above, a touch input will be made when the two transparent conductive layers contact. One of the two conductive layers constructs the X-coordinate circuit while the other layer constructs the Y-coordinate circuit. 

As indicated below, the X-electrodes form the top layer while the Y-electrodes form the bottom layer.

(1) X(+) will be Vcc(5V) while X(-) will be Ground(0V).

(2) Voltage is applied between the X(+) and X(-) electrodes.

(3) When the touch screen is touched (pressed), the voltage of the X-coordinate on the top layer will be detected at the Y- electrode (A_in) on the bottom layer.

Example: If the point A is pressed, an X-coordinate voltage of 2.5V will be detected at A_in on the bottom layer.

Another example: If the point B is pressed, an X-coordinate voltage of 4V will be detected at A_in on the bottom layer.

(4) The detected voltage will be converted into digital data (A/D conversion), and the coordinate position of the X-direction will be recognized.

(5) When Voltage is applied between the electrodes Y(+) and Y(-). The touched point of the Y-direction will be recognized in the same manner as the X-direction; the voltage of Y-coordinate will be detected on the top layer.

(6) The detection processes of the X & Y-coordinates as described above is repeated alternately in order to detect the input point.

2. Detection Mechanism of 5wire resistive touch screen

As described above, a touch input would be made when the two transparent conductive layers contact. One of the two conductive layers constructs the X and Y coordinate circuit while the other layer constructs the detection circuit. 

As in the below figure, the electrodes A to D are formed on the corners of the bottom layer while the top layer works as detection circuit.

X-coordinate Detection

As indicated in the figure below, the voltage applied between the electrodes A and B is Vcc (5V) while between the electrodes C and D is Ground (0V). 

As the touch screen is touched, the top and bottom layer will contact, then the voltage of the X-coordinate circuit at the touched point will be detected at the detection circuit A_in.

Example: If the top and bottom layers contact at the point "A", an X-coordinate voltage of 2.5V will be detected at A_in on the top layer. 

Another example: If the top and bottom layers contact at the point "B", an X-coordinate voltage of 4V will be detected at A_in on the top layer. 

The detected voltage will be converted into digital data (A/D conversion), then the coordinate point of the X-direction will be detected.

Y-coordinate Detection

As indicated in the figure below, the voltage applied between the electrodes B and C is Vcc (5V) while between the electrodes A and D is Ground (0V). 

Just like the X-coordinate detection, voltage of the Y-direction will be detected at A_in on the top layer.

Example: If the top and bottom layers contact at the point "A", an Y-coordinate voltage of 2.5V will be detected at A_in on the top layer. 

Another example: If the top and bottom layers contact at the point "B", an Y-coordinate voltage of 4V will be detected at A_in on the top layer. 

The detected voltage will be converted into digital data (A/D conversion), then the coordinate point of the Y-direction will be detected.

What is the structure of a resistive single touch screen?

4wire and 5wire resistive touch screen is a two-layer structure, two materials (film or glass) with ITO are attached with a gap between them so that the ITO layers are facing each other. 

Touch input will be made as the top layer is pressed down and the two ITO layers contact. 

There are insulators called spacing dots between the top and bottom ITO layers. These spacing dots prevent unintended contacts (inputs) of the ITO layers when not pressed.

Can I use a resistive single touch screen with mitten?

Of course, a resistive single touch screen can be used with mitten.

How long is the operation life of a resistive single touch screen?

12 million touches are guaranteed for a 4 wire touch screen.

37 million touches are guaranteed for a 5 wire touch screen.

Does a resistive single touch screen recognize multiple touched points simultaneously?

Resistive Multi touch screen Type supprots dual touch.

Resistive single touch screen type such as 4wire and 5wire supports single-touch only. If two points are touched, the middle point will be detected.

If I need a resistive single touch screen whose specifications are tailored to my needs.

We can provide a resistive single touch screen customized to your requested specifications.

Please contact us for more details.

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