How does a resistive touch screen work

2018-11-19 15:32:16

Working principle of resistive touch screen

One: the composition and implementation principle of the touch screen

     Resistive touch screen is a sensor,He converts the physical position of the touch point (X.Y) in the rectangular area into a voltage representing the X coordinate and the Y coordinate.

     Many LCD modules use resistive touch screens，These screens can use four-wire, five-wire, seven-wire or eight-wire to generate the screen bias voltage while reading back the voltage at the touch point.

Two: touch screen principle

     The touch screen consists of two transparent layers superimposed on top of each other，Four- and eight-wire touch screens consist of two layers of transparent resistive material with the same surface resistance，Five- and seven-wire touch screens consist of a resistive layer and a conductive layer。

     Usually an elastic material is used to separate the two layers，When the pressure on the surface of the touch screen (such as pressing through a pen tip or finger) is large enough，There is contact between the top layer and the bottom layer.

     All resistive touch screens use a voltage divider principle to generate voltages that represent the X and Y coordinates.

Three：Working principle of resistive touch screen

     Resistive touch screen is mainly controlled by pressure sensing，It is composed of a display screen and a resistive film screen that closely fits the display screen.

     This resistive film screen is usually divided into two layers，One layer is a base layer made of glass or plexiglass, and its surface is coated with a transparent conductive layer.

     The outer layer of the base layer is pressed against the hardened and scratch-resistant plastic layer that we normally touch directly，The inside of the plastic layer also has a conductive layer, and the two conductive layers are separated.

     When we touch the screen with our fingers or other objects，Two conductive layers in contact，Change in resistance，The controller judges the coordinates of the contact point according to the specific change of the resistance and performs corresponding operations.