What’s Resistive Touchscreen? Resistive touch screen suppliers.

As there are more resistive touch screen suppliers on the market which make resistive touchscreens more popular and prices are falling down, so that resistive technology is becoming more widely used. In order to choose the best touch screen technology, application designers must consider the application requirements. Resistive touch screen technology requires only a simple printed circuit board design, unlike capacitive and inductive touch screen technology, which requires electrode or coil etch on the printed circuit board. Because the touch screen is directly overlaid on the display, so that the printed circuit board space required for mechanical switches or capacitive touch key electrodes can be saved. Resistive touch screens are not recommended for use in harsh environments, such as mines or work sites that are often exploding or dusty. Little damage on resistive touch screens can affect touch accuracy and linearity.

Resistive Touchscreen

1.The working principle of resistive touchscreen:

1. A resistive touch screen is a transparent glass panel with a surface covered with a touch-responsive film.

2. The resistive touch screen panel consists of two resistive layers (ITO) and separated by the dot in between.

3. The two thin film layers of the resistive touch screen form a resistor network that acts as a voltage divider for the touch position detection function.

4. The touch screen causes a voltage change on the voltage divider formed by the resistor network. This voltage is used to determine the contact position of the touch screen.

5. The touch screen controller (TSC) converts the captured analog voltage signal into a digital touch coordinate signal. A built-in analog-to-digital conversion channel acts as a voltmeter for measuring analog voltage.

6. After touching the screen, the touch controller functioning as a voltmeter first applies a voltage gradient VDD at the X+ point and a ground voltage GND at the X-point. Then, the analog voltage on the Y-axis resistance is detected, and the analog voltage is converted into a value, and the X-coordinate is calculated using an analog-to-digital converter. In this case, the Y-axis becomes a sensing line. Similarly, the Y coordinate can be measured by applying a voltage gradient at the Y+ and Y-points.

7. Some touch controllers also support touch pressure measurement, or Z-axis measurement. When measuring the Z-axis coordinates, a voltage gradient is applied to the Y+ axis and the X-axis.

Resistive touch screen suppliers

 2.The 3 types of resistive touchscreen.

According to the number of sensing lines on the touch screen, the resistive touch screen can be further divided into three categories: 4-wire resistive touchscreens5-wire resistive touchscreens and 8-wire resistive touchscreens . The strip electrodes of the 4-wire touch screen are mounted on two different resistive layers (X+, X- are on the same layer, Y+, Y-the other resistive layer). The 5-wire touch screen has only round electrodes (X+, X-, Y+, and Y-) on the bottom layer. The top layer is used to measure the voltage during the touch process and the voltage gradient is applied only to the bottom layer.

The 8-line touch screen works like a 4-wire touch screen. Just add a reference voltage line to each line, so the final number of buses reaches 8. The new four lines are used to provide reference voltages to the original four lines. The 8-wire touch screen uses the measurement principle of a proportional measurement analog-to-digital converter.

Because of its low cost and simple touch sensing algorithm, 4-wire touch screens are widely used in low-end consumer electronics. 5 wire and 8-wire touch screens are used primarily for expensive high-end medical equipment and important industrial controllers. Eagle Touch as an experienced touch screen manufacturer we provided both 4 wire resistive touchscreens and 5 wire resistive touchscreens.

Resistive touchscreen manufacturers. Touch screen.

Touch screen performance comparison

The resistive touch screen works in an environment completely isolated from the outside world. It is not afraid of dust, moisture and oil. It can be touched by any object and is suitable for industrial control. The disadvantage is that because the outer layer of the composite film is made of film, too much force or sharp touch may scratch the touch screen which will be unable to work anymore.

The capacitive touch screen has a high resolution and a good light transmittance, which can well meet various requirements. This type of touch screen is common in public places. However, the capacitive touch screen uses the human body as an electrode of a capacitor. When a conductor is close to and a sufficiently large capacitance is coupled between the ITO working surface of the interlayer, the current flowing away causes a malfunction of the capacitive touch screen; There is no response when touched with gloves or a hand-held insulating object because of the increased insulation medium.

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The infrared touch screen determines the touch position by measuring the on and off of the infrared light, regardless of the material of the transparent baffle selected for the touch screen (some have no baffles at all). Therefore, the use of a baffle with good light transmission properties, and anti-reflective treatment, can get a good visual effect. However, due to the limitation of the volume of the infrared emission tube, it is impossible to emit high-density infrared rays, so the resolution of such a touch screen is not high. In addition, since the infrared touch screen relies on infrared sensing to work, external light changes, such as sunlight or indoor lights, can affect its accuracy.

The surface acoustic wave technology is very stable, and the controller of the surface acoustic wave touch screen calculates the touch position by measuring the position of the decay moment on the time axis, so the accuracy is very high. The surface acoustic wave touch screen also has a third axis (z axis), that is, a pressure axis – the amount of power that the user touches the screen can be obtained by calculating the amount of attenuation at the attenuation of the received signal, which can be divided into up to 256 levels of force. The greater the power, the wider and deeper the attenuation gap on the received signal waveform. Of all the touch screens, only the surface acoustic wave touch screen has the ability to sense touch pressure.

Application

Resistive touchscreen manufacturers. Touch screen. 1

According to the analysis of the structure, principle and performance characteristics of the touch screen, the applicable occasions of different touch screens are as follows:

4 wire touch screen: not afraid of dust, oil and photoelectric interference, fear of scratch is its main defect. Applicable to public places with fixed users, such as industrial control sites, offices, homes, etc.

5-wire resistive touch screen: excellent sensitivity and transparency, long service life, not afraid of dust, oil and photoelectric interference, suitable for all kinds of public places, especially suitable for sophisticated industrial control sites.

Eagle touch as one of the resistive touchscreen manufacturers in China, we provide both resistive touchscreen and Pcap touchscreen.