In the world of resistive touchscreen technology, the choice between 4-wire and 5-wire resistive touchscreens is an important one. Both types serve various purposes in electronic devices, but they differ in construction, functionality, and suitability for specific tasks.
While 4-wire touchscreens are cost-effective and suitable for simple applications, 5-wire touchscreens offer superior durability and accuracy, making them better for more intense use. Therefore, the choice for either depends on project-specific requirements.
The article below offers a thorough comparison of 4-wire versus 5-wire resistive touchscreens, highlighting their strengths, weaknesses, and ideal applications.
Similarities
Before we discuss how these touchscreens are different, it’s important to know how they’re similar in many ways.
Basic Design
A resistive touchscreen (both 4-wire and 5-wire) consists of four layers. It has two primary layers: a stable bottom layer made out of glass and a flexible top layer made out of Polyethylene (PET). The top side of the bottom glass layer and the underside of the top PET layer are then coated with a metal compound called Indium Tin Oxide (ITO).
On top of the resistive coating of the glass side, spacer dots are placed to prevent the ITO layers from touching each other and initiating a false touch. When the top layer is pressed down, it touches the bottom layer which allows the touchscreen to register a touch.
Multi-Touch
Because of their basic design and the way they measure touch, which we’ll explain more later on, both 4-wire and 5-wire panels aren’t that suitable for multi-touch applications. Currently, there are some ways to implement 2-touch with 5-wire panels, which allows for zoom and pinch functionality, but that’s the maximum extent. For multi-touch purposes, capacitive touchscreens are more common.
Differences
Even though their basic principles are similar, there are some clear differences between the two technologies as well.
Mechanism
The first difference between these resistive touchscreens is how many wires they use, which influences other factors as well.
4-wire touchscreens are the simplest resistive touchscreens. They have two wires connected to the left side of the top PET layer and two wires on the right side. The bottom glass layer has two wires on the bottom side and two wires on the upper side. The 4 wires are referred to as X+ (left), X- (right), Y+ (top), and Y- (bottom). A uniform, unidirectional voltage gradient is then applied to the ITO layer of the top sheet.
As an example, the voltage gradient looks like this on the top layer: 5V is applied to the left wire (X+) and 0V is applied to the right wire (X-). When the top and bottom layers touch, the exact middle would give a voltage reading of 2.5V. In this case, the system would identify that the x-coordinate is in the exact middle of the screen. The same is then done for the y-coordinate (using Y+ and Y-). This voltage application sequence can also be reversed depending on the system.
5-wire touchscreens are different in that they have four wires along the perimeter of the bottom layer that are connected by electrodes at the corners, whereas a fifth wire runs along one side of the top layer. This means both the x- and y-coordinate are measured at the bottom layer.
In terms of user experience, these systems aren’t operated any differently. However, the different mechanisms do mean other differences are noticeable between the two systems.
Durability & Accuracy
One of the common problems of 4-wire touchscreens is that sustained usage wears down the top ITO layer. This means the 4-wire touchscreens wear out more easily over time and also result in decreased performance of the touchscreen.
Because 5-wire touchscreens only measure the coordinates of the touch at the bottom panel, they don’t have this problem and therefore have an advantage in terms of durability and long-term accuracy.
However, it must be noted that the mechanical and environmental durability of the ITO layers has improved significantly in the past years. This does mean the difference between these touchscreens isn’t as substantial as it used to be.
Cost
Given the difference in technology and performance, there’s also a price difference. 4-wire touchscreens are commonly known as the most cost-efficient option. On the other hand, 5-wire touchscreens cost more but this does result in longer durability and more reliable performance.
Which Touchscreen Is Better?
Which touchscreen better suits your needs depends on your requirements.
First of all, 4-wire touchscreens are more cost-effective and oftentimes easier to integrate into electronic systems. However, they’re more susceptible to wear and tear and won’t last as long as their counterparts. For this reason, 4-wire touchscreens are ideal for use in lower-end consumer electronics as well as simple POS terminals, kiosks, and information terminals.
5-wire touchscreens are more costly to implement but do provide longer-lasting durability and accuracy. For this reason, their longevity ensures more accurate input throughout the years.
It must be noted that these days resistive (either 4-wire or 5-wire) touchscreens aren’t the norm. Rather, capacitive touchscreens are more commonly used because they offer a range of advantages that resistive touchscreens lack including multi-touch functionality, lower wear and tear, and better responsiveness.
