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What is The Working Principle Of The Smart Industrial Touchscreens?

With the continuous development and innovation of science and technology, people's living standards are getting higher and higher. Touch screens are also widely used by people. It brings a lot of convenience to people's work and life. The application in the market is also very hot. It can be seen in various fields. Let’s take a look at the working principles of various types of smart industrial touchscreens:

1. Working Principle Of Resistive Touch Screen:

The working principle of the resistive touch screen is mainly through the principle of pressure sensing to realize the operation and control of the screen content. The body of this touch screen is a multi-layer composite film that fits well with the surface of the display. The first layer is a glass or plexiglass bottom layer, the second layer is an interlayer, and the third layer is a multi-resin surface layer. The surface is also coated with a transparent conductive layer. It is covered with a layer of hardened, smooth and scratch-resistant plastic layer on the outer surface.

The conductive layer and the glass layer sensor on the surface of the multi-element resin are separated by many tiny interlayers. Electric current passes through the surface layer, and when the surface layer is touched lightly, it touches the bottom layer. The controller reads the corresponding current from the four corners and calculates the distance of the finger position at the same time. This touch screen uses two highly transparent conductive layers to form a touch screen, and the distance between the two layers is only 2.5 microns.

When a finger touches the screen, the two conductive layers that are usually insulated from each other make a contact at the touch point. Because one of the conductive layers is connected to a 5V uniform voltage field in the Y-axis direction. Make the voltage of the detection layer change from zero to non-zero, after the controller detects this is turned on. Perform A/D conversion and compare the voltage value obtained with 5V. Then the Y-axis coordinate of the touch point can be obtained, and the X-axis coordinate can be obtained in the same way. This is the most basic principle common to all resistive technology touch screens.

2. Capacitive Smart Industrial touchscreens

The capacitive smart industrial touchscreens is a transparent special metal conductive material attached to the glass surface. This kind of inductive touch screen consists of five layers. The first layer is a glass bottom layer, the second layer is a conductive layer, the third layer is a glass sensing layer, the fourth layer is an anti-reflective matte or bright surface layer, and the fifth layer is an anti-noise protective layer. When the finger touches the surface of the capacitive touch screen, the sensing method is that the voltage is connected to the four corners of the glass layer.

The electrode spreads the voltage across the glass layer and establishes a constant voltage electric field. At the same time, the capacitance of the contact will change. Make the frequency of the oscillator connected to it change. By measuring the frequency change, the touch position can be determined to obtain information. Because the capacitance varies with temperature, humidity or grounding conditions. Therefore, its stability is relatively poor, and drift phenomenon often occurs. In addition, when the surface layer is touched, current flows from the four corners of the glass layer. The controller calculates the distance of the current to the finger position. In order to determine the exact location of the touch.

3. Infrared touch screen

The working principle of this infrared touch screen is relatively simple. Just add the light spot distance frame on the display. There is no need to coat the screen surface or connect to the controller. Then, infrared emitting and receiving sensing elements are arranged on the four sides of the light spot away from the frame. On the surface of the screen, an infrared detection net is formed. When any touch object touches a certain point on the screen, it will block the two horizontal and vertical infrared rays passing by that position.

The computer can calculate the touch point position instantly. The infrared touch screen is not interfered by current, voltage and static electricity. Suitable for some harsh environmental conditions. Because the infrared touch screen has no capacitance charging and discharging process when it is working. The response speed is faster than the capacitive type, but the resolution is lower.