Difference between capacitive and resistive touch and determining the touch sensitivity

Difference between capacitive and resistive touch and determining the touch sensitivity

Hey Alfonso!

First of all let us start with capacitive touch screen. This kind of screen is made of coated material with glass pane. The material with which this glass is coated, can store electrical charge in it. So electrical charge stores in these types of screens.

As we all know that we humans have also electric charge in our body. So when our finger touches the screen, the charges on the screen transfer in our finger. There are some oscillators circuits in the screen which will sense that there become some decrease in the charge and where you touch, these circuit will spot this location exactly and will transfer the information to proceed your command.

IPhone is one of the best example of this screen.

Now let us talk about Resistive touch screen. The same is the case with these types of screen. These are made of glass panel but are coated with three different layers. The two layers using spacers are kept apart and the whole setup is covered by the whole setup. First layer is conductive, second as Resistive and third is Scratch resistant layer.

Nokia N97 is the best example of these types of screens.

Difference between capacitive and resistive touch and determining the touch sensitivity

Thanks Tunacao_Caaron1 and Kenshe.

Now I know what's the difference between the two.

Thank you very much for your answers. 

Thanks Techyv

Difference between capacitive and resistive touch and determining the touch sensitivity

There are actually two types of touchscreens: resistive and capacitive. Although touchscreen devices are very common nowadays from Smartphones, tablets, to ATM machines and even tables, this is actually not a new invention as you may think. The first touchscreen was invented back in the 1960s and has gone through many changes to become the touchscreen we use today. The most common type is the resistive touchscreen.

Excluding modern Smartphones, tablets, and trackpads, the majority of touchscreens we come in contact with are resistive touchscreens. This type of touchscreen depends on resistance. The pressure you apply on the screen causes the screen to respond. This type of touchscreen is composed of two thin layers separated by a thin gap.

Although these are not the only layers in the resistive touchscreen, these two layers both have a coating on one side with the coated sides facing one another inside the gap. When these two layers of coating touch one another, it passes a voltage which in turn is processed as a touch in that location.

When your finger or stylus touches a resistive screen, it creates a slight pressure on the top layer which is then transferred to the adjacent layer consequently initiating the flow of signals. With capacitive touchscreens, surprisingly, this is the touchscreen that was first invented. The first capacitive touchscreen was invented nearly 10 years before the first resistive touchscreen.

Yet, capacitive touchscreens nowadays are highly accurate and respond instantly when lightly touched by a human finger. A capacitive touchscreen is normally made of one insulating layer like glass, for example, coated with a transparent conductive material on the inside. Because the human body is conductive, meaning electricity can pass through it, the capacitive screen can use this conductivity as input.

When your finger touches a capacitive touchscreen, you cause a change in the screen’s electrical field. This change in the electrical field is registered and the location of the touch is determined by a processor.