The Fundamentals of 5-Wire Resistive Touchscreens

Please visit our website for more information on this topic.

--

Resistive touchscreens have remained a leading touch sensor technology for over 40 years. They offer economical touchscreen solutions featuring two layers of electrically resistive material separated by spacer dots. With a tap or touch command on the display surface, the two layers come in contact resulting in the detection of touch inputs. Out of the different resistive touchscreens, 5-wire is the most widely used.

Here are the basics of 5-wire resistive touchscreens.

5-wire resistive touchscreens are the advanced version of resistive touch sensors that use a specific configuration of electrodes- an essential component to detect touch commands. Unlike its counterpart 4-wire and 8-wire, which have opposing pairs of conductive X and Y buss bars, 5-wire resistive touchscreens utilize electrodes placed on the four corners of the substrate layer.

The 5-wire resistive touchscreen technology has transparent conductive coatings on the inside of both the top and bottom layers, separated by tiny spacer dots. The four electrodes at the corners of the bottom conductive layer are connected to the flexible circuit tail of the sensor. The top layer is connected with just one wire and used as a voltage probe for the sensor. When pressed by touch, it sends the voltage in alternating X and Y planes to the controller and the touch coordinates are then calculated.

This unique configuration makes 5-wire resistive touchscreens preferred over other touchscreen technologies.

Why Choose 5-Wire Resistive Touchscreens?

Touch-China Product Page

Durability is a significant feature required in a touch application. Resistive touchscreens are known for durability; however, 5-wire technology offers the highest durability of all.

The sensor life of 5-wire resistive touchscreens is comparatively more than 4-wire, which doesnt have good sensor life. A 4-wire sensor can get damaged by only a few hard strokes of a fine point stylus and typically offers 4 million touches or less on the same spot with finger operation. The 5-wire touch sensor, on the other hand, is not affected much by ITO fracturing because it does not need to maintain actual values of current flow to remain linear. 5-wire resistive touch sensors can achieve 35 million touches on the same point with finger activation.

5-wire resistive touchscreens are relatively sensitive. It means theres no need to press it hard or forcefully to register touch commands. They require light-pressure touch with a physical object to register the input.

5-wire resistive touchscreens can be operated using any physical object- a bare finger, a gloved finger or a stylus. They do not depend on human capacitance to register touch commands such as with capacitive touch screens.

However, there are graphical user interfaces (GUIs) in applications facing challenging environments that only resistive touch sensors can endure. At the same time, they also demand multi-touch capability, which is typically unavailable in standard resistive touchscreens.

To overcome this limitation, A D Metro has elevated the feature of standard 5-wire resistive sensors through their advanced two-touch resistive touchscreen controller. This controller delivers the two-touch capability to 5-wire resistive touch sensors.

A D Metros two-touch 5-wire resistive touchscreen controller offers 100 touch points per second for single touch and for multi-touch -70 touch points per second, allowing fast and smooth touch operations. Through this innovative multi-touch solution, 5-wire resistive touchscreens can be made capable of two-touch operation along with pinch, zoom, rotate and drag gestures. Furthermore, the two-touch controller allows HID plug & play in Windows to assist in seamless integration.

Overall, A D Metros two-touch controller delivers new capabilities to the reliable, tried and tested 5-wire resistive touchscreens.

Fuelled by the evolution in technology, at present, a wide range of options are available for touchscreens. Thus, when it comes to choosing the one, the decision entirely depends on the convenience it can add to the device usage.

However, a large number of industries prefer resistive touchscreens for their application. It offers multiple benefits, cost-effective and multi-touch operation ability (gloved and bare finger and stylus), are some of them.

Talking about the internal structure of a resistive touchscreen, it comprises two layers of glass and film, coated with a transparent conductive material both of which are separated by an air gap and microdots. When the flexible top/ front layer is pressed, the two layers come in contact with each other, and the voltage at the point of contact is read through conductors at the edges of each layer in the case of 4-wire or just the bottom layer in the case of a 5-wire. The voltage read at the touch point determines the location of the touch point.

Further, based on design, the two most common types of resistive touchscreens we have, are 4-wire resistive touchscreens and 5-wire resistive touchscreens.

If you are considering a resistive wire touchscreen, but confused with the design, here are the subtle nuances that can help you understand the difference between the 4 and 5 wired resistive touchscreens.

4-wire resistive touchscreens
In 4-wire resistive touchscreens, Each of the two layers has a conductive buss bar printed along two opposite edges. One layer will have buss bars located top and bottom with the other layer having buss bars located on the left and right edges. The controller will apply a DC voltage across one of the layers with the positive connected to one bar and the negative connected to the other. This will create a voltage flow through the conductive coating of that layer that varies in voltage level depending on how close it is read to either the positive buss bar or the negative buss bar. When a touch event occurs, the opposite layer comes in contact with the voltage layer and the controller uses the opposite layer as a voltage probe to read the voltage at the touch point. The controller can then determine where the touch point is in that one plane (either X or Y). To get the other plane, the controller flips the functions of the layers so that the same happens but in X rather than Y or vice versa. This flipping of layer functions happens typically more than 100 times per second, so the X and Y coordinate readings have no lag in reporting.

The benefit you can have with 4-wire resistive touchscreens is the cost-effective solution it offers. It consistently remains the cheapest touch panel for low end applications. .

5-wire resistive touchscreens
5-wire touchscreens measure voltage from the lower layer only. Unlike 4-wire resistive touchscreens that use both layers to measure voltage, in a 5-wire touchscreen, the upper layer is simply a voltage probe that is used only to measure the voltage of the bottom layer. Like the 4-wire, the 5-wire measures voltage in one plane then flips the voltage application to the other plane but it is done only on the bottom layer which has a special conductor pattern around the perimeter that allows for this function the be carried out on the one layer. It means the micro-damage to the upper no load voltage probe layer wont obstruct the touchscreens performance or accuracy.

The reasons why 5-wired touch panels are preferred for commercial applications over 4-wire resistive touchscreens, are that 5-wire models are more durable, accurate and long-lasting.
Though it costs slightly more, 5-wire resistive touchscreen is an investment that can pay off in the long run.

Final Words!
With A D Metro, you can get both- durable and cost-effective resistive touchscreens with different enhancements to meet the more demanding requirements of several applications. The resistive touchscreens from A D Metro, include 4 and 5 wire, and are resistant to contamination and offers great sealable compatibility with NEMA 4, 12 and IP65 enclosures. A D Metro also offers their flagship armoured resistive version called ULTRA which offers many more benefits over standard resistive including a 10-fold increase in life expectancy.

For more Five-Wire Resistive Touch Screeninformation, please contact us. We will provide professional answers.