Did you know there are many types of touch screen technologies, each with different functions and applications? Resistive touch screen technology is one of the most common types, offering great versatility. Below, let’s look at the benefits and any limitations of resistive touch screens compared to other technologies, including projected capacitive touchscreens (PCAP). We’ll also discuss ULTRA touch screens, a more durable option.
1. Resistive Touch Screen Basics
For resistive touch screens to work, you must put a bit of pressure to the screen, such as pressing a finger to it. When you do so, the sensor within is activated. What specifically happens is the two conductive coated layers below the surface touch, and the controller locates the touch point. The two layers usually use Indium Tin Oxide (ITO).
2. Understanding Resistive Touch Screens
The resistive touch screen features a top film that the finger comes into contact with. Directly below that is the top electrode. Beneath that layer is an air gap, then a bottom electrode layer, and, finally, the display.
The film is usually made of polyester. The two conductive layers are usually made of ITO because it is transparent and durable.
Resistive touch tech comes in 4-wire, 5-wire, and 8-wire designs, each one using analog switch technology. While they all read voltages to obtain touch position, a 4-wire design uses the top and bottom layers to represent the touch coordinates (X and Y). One layer is used to represent X and the other layer for Y. When a voltage gradient is applied to either the X or Y layer, the opposite layer reads the voltage to determine where the touch in that plane is. Then, the operation flips so that the voltage probe layer becomes the voltage gradient layer, and the same process happens to determine the touch in the opposite plane. That happens over a hundred times a second.
However, 4-wire sensors are not durable because the ITO is brittle, and since the top surface layer is flexible, the ITO will fracture over time, causing a higher and non-uniform resistance in that spot and skewing the voltage reading. The 5-wire system solves this problem by having the X and Y gradient reside on the bottom layer, which is usually glass and does not flex, helping to keep the ITO from fracturing while maintaining a forever accurate voltage gradient.
That is possible because of the linearity pattern applied around the bottom layer’s perimeter, instead of the 4-wire buss bar design. The top layer is only used as a voltage probe, and even if the ITO fractures, the voltage reading will always have the same accuracy since the probe has no load and will continue reading until the ITO is so badly fractured that it cannot read a voltage at all. That makes 5-wire last 30 times longer than 4-wire.
3. Resistive vs Capacitive Touch Comparison
Resistive touch screens differ from capacitive in design, with each having advantages and disadvantages. Resistive touch relies on physically pressing two layers together, as described earlier.
This pressure activation is less sensitive than the capacitive touch screen that senses touch through electrical properties of the human body. In other words, our natural conductivity triggers the capacitive touch design to work. This increased sensitivity may make for greater accuracy.
Capacitive touch screens are also generally more durable than resistive. However, this design is typically more expensive than resistive touch, so capacitive will not fit every project budget. Along with being the more affordable of the two, resistive touch screens also usually have a better resolution.
With capacitive design, there is also the risk that it’ll activate before you touch the screen. That means it can be unreliable.
4. Exploring Resistive Touch Panels
Resistive touch panels usually have a standard polyester top layer that you touch. Unfortunately, this surface can get worn over time and is susceptible to both water ingress and vandalism.
That’s where A D Metro’s ULTRA Armoured touch screen has a major advantage with its blend of materials. The ULTRA improves durability far beyond the standard polyester switch layer and touch surface by instead using a special glass surface and polyester laminated switch layer. That provides extra stiffness, along with the sensor being waterproof to withstand all weather and keep operating.
5. Choosing the Right Resistive Touch
The right type of resistive touch screen depends on the intended use. The environment, input methods, and desired lifespan are all important factors to consider.
In harsher weather, for example, ULTRA Armoured touch screen sensors remain reliable by working through all types of weather. Plus, ULTRA works on both glove and stylus operation, for use in many situations.
6. Projected Capacitive vs Resistive Touch Screen Debate
Selecting the right touch screen tech depends on what the situation requires. ULTRA Armoured touch screen sensors have excellent durability, with one and two touch operation in any weather condition for fixed or mobile applications with glove or stylus use.
In comparison, resistive touch screens naturally resist electromagnetic interference (EMI) and radio frequency (RF) interference, so they are not at risk of interference from either activating the sensor. That makes them well-suited for front-line military use as they won’t interfere with other sensitive equipment. And, unlike capacitive touch, they are electronically stealthysince they don’t emit any radio frequency making them essential for front-line military applications.
With that said, projected capacitive touch designs have clearer displays than resistive and multi touch functionality. A D Metro has developed a 2-touch resistive controller to provide the broader range of multi-touch tasking. The projected capacitive design is at risk of false activationsif exposed to water.
7. Benefits of Resistive Touch Screens
While they don’t have all-weather operation, standard resistive touch screens have EMI/RF immunity, making them reliable in all situations. They offer a lot of uses. The applications are potentially many, although ULTRA technology is able to work in all weather conditions and not affected by temperature changes while providing multiple input methods.
8. Projected Capacitive vs Resistive Touchscreen Showdown
After comparing the two, it is clear that projected capacitive and resistive are suited for different situations, each offering benefits and drawbacks, based on application. A D Metro’s ULTRA technology has the extra durability to withstand wear and tear, and it is the easiest to use with wet conditions. It also has multiple ways to input, whether gloves or stylus is preferred.
