Capacitive vs. Infrared vs. Nano Touch Film: Choosing the Right Touchscreen Technology for LCD Displays

There is a touchscreen kiosk in the library positioned by a window. It works fine when there is no sunlight. But as soon as the sun slants in, the touchscreen becomes unresponsive, jumps around erratically, and sometimes stops working altogether. The supplier replaced the unit twice, but the problem persisted. The fault lay not with the machine itself, but with the choice of touch technology. It was an infrared touchscreen device, which is inherently susceptible to strong light and infrared interference. Moving it to a different location or switching to a capacitive touchscreen would have resolved the issue immediately.

Choosing the right touch technology may seem like a minor matter, but getting it wrong can completely ruin the user experience. This article will introduce the three mainstream touch technologies for displays, starting with their principles, advantages and disadvantages, before providing a clear comparison and a selection guide.

Overview of Touchscreen Technology

Touch technology is a sensing solution that enables a screen to detect and respond to touch input from a user’s finger or stylus for interaction. To use an analogy, touch technology is like fitting the screen with a layer of ‘sensing skin’. The difference between various technologies lies in the principles by which this ‘skin’ perceives touch—some rely on light, some on electricity, and others on conductive films. Different principles mean different characteristics: some are sensitive to light, some to water; some can cope with large sizes, whilst others can only cope with small ones.

Types of Touchscreen Technologies

The three mainstream touch technologies used in displays are infrared touch, capacitive touch and nano-touch film. They differ in terms of operating principle, number of contact points, size, cost and environmental adaptability, factors which directly determine the touch experience and applications of the display.

Capacitive Touch

Capacitive touch achieves touch functionality by incorporating a transparent conductive layer between the LCD display and the protective glass. Capacitive touchscreens rely on an electric field. The screen surface is charged with a uniform electric field. As your finger which acts as a conductor touches the screen, it draws away a small portion of the electric field at that point. The screen detects a change in capacitance at a specific location and thereby pinpoints the touch point. Mobile phone screens operate on this principle.

Based on this principle, they support multi-touch (such as ten-point touch or more), offer a smooth feel, respond quickly, and are water- and dust-resistant, whilst remaining unaffected by ambient light. The sacrifice is that they are sensitive to ‘conductors’: touching the screen with a non-conductive material will not register a touch, and water droplets on the screen or excessive humidity can cause false touches and erratic behaviour. Manufacturing large-sized screens presents significant technical challenges, leading to soaring costs.

Infrared Touch

Infrared touch features infrared emitters and receivers mounted on the display’s bezel, which emit a dense pattern of invisible light across the screen’s surface. When a finger is placed over the screen, it blocks certain beams of infrared light. The receiver detects that ‘there is no light here’, and by calculating the intersection points, it determines exactly where you are touching.

Infrared touchscreens can be operated by both conductive and non-conductive objects, such as fingers, styluses and gloved hands. They are highly resistant to interference and are unaffected by electrical currents, voltages or static electricity. Their drawbacks stem from the optical principles on which they are based—they are susceptible to strong light and intense infrared radiation. Direct sunlight or exposure to strong infrared lamps can lead to misreadings, whilst dust accumulating on the bezel and blocking the light beams can also cause malfunctions. They offer a relatively low cost for large touch screens.

Nano Touch Film

Nano-touch films are typically affixed to the rear of glass or acrylic. They are capable of detecting electrostatic fields through glass or acrylic of a certain thickness, forming a touch-sensing matrix via the interwoven X- and Y-axis nanowires within the film. When a finger touches the glass or acrylic from the opposite side, the touch film detects changes in the electrostatic field and transmits the signal to the control chip. After processing, the touch position is determined, thereby enabling touch operation.

It features a compact structure, is lightweight, transparent and frameless, and is easy to install on glass or acrylic panels. It is insensitive to external light sources, and changes in ambient light don’t affect its operation. It has a long service life, and products manufactured using this technology offer good waterproofing, dustproofing and explosion-proofing capabilities, whilst also supporting multi-touch functionality.

However, its manufacturing process is highly demanding, relying heavily on the lamination process and edge wiring. Poor workmanship can easily lead to edge malfunctions and position drift. Overall, it tends to be customised and relatively costly. Its sensitivity and response speed are slightly inferior to capacitive screens.

Comparison of Capacitive, Infrared, and Nano Touch Technologies

Choosing the Right Touch Technology for Your LCD Display

When choosing the right touch technology, don’t get bogged down in the technical details; first consider the requirements of your LCD display, then take your assigned seat:

Large size, good value for money, easy to maintain → Choose infrared touch screen. This is the mainstream choice for large touch screens and interactive displays. Installation and subsequent maintenance are also relatively straightforward. As it doesn’t involve physical contact with the screen, it has virtually no impact on the display image. If it breaks, simply replace the frame. It's a safe and reliable choice for most applications.

Small to medium sizes, smooth operation, slim all-in-one design → Choose capacitive touch screen. Capacitive touch is suitable for small to medium-sized touchscreens, self-service kiosks and interactive devices. It is ideal for applications requiring frequent tapping, swiping and zooming.

For applications on shop windows and irregularly shaped surfaces → choose Nano Touch Film. Its unique design allows users to interact directly with the glass surface whilst preserving the glass’s original appearance and transparency. Specifically designed for interactive shop windows, glass display cabinets and customised interactive displays with irregular shapes.

If your device needs to support multiple users interacting with the screen at the same time, you should also check whether the number of touch points meets your requirements. You don't want to end up in an awkward situation where the screen gets chaotic as soon as several people touch it at once.

Final Thoughts

The three brothers of touchscreens are not absolutely ’ good ’ or ’ bad ’. It’s simply a matter of suitability. You first consider the display’s size, placement, whether it will be behind glass, and the number of users who will be touching it simultaneously, and then select a solution based on these key factors; you can't really go wrong with it.

Still not sure which touch technology would be best for your project? We will be happy to advise you on your choice of touchscreen!

VETO is a display equipment manufacturer with over 10 years of industry experience, and its products are exported to numerous countries and regions. We operate multiple production lines and possess well-established OEM/ODM customisation capabilities. Through strict quality control, timely technical support, and comprehensive after-sales service, we provide our customers with reliable products and services.

Frequently Asked Questions

1. What are the common applications of touch displays?

Touchscreens are widely used in a variety of devices, such as mobile phones, tablets, cash machines, self-service kiosks, interactive whiteboards and medical equipment.

2. What are the different types of touchscreens?

There are various types of touchscreens, including resistive, capacitive, infrared and nano-touch. This article primarily introduces the three mainstream touch technologies commonly used in displays.

3. What is the difference between single-touch and multi-touch?

Put simply, a single-touch screen can only be operated with one finger and doesn’t support the use of multiple fingers. Multi-touch allows for simultaneous operation with multiple fingers.

4. Does touch technology affect a device’s battery life?

Yes, touch technology does affect a device’s battery life as it requires more power to process touch input. However, thanks to technological advancements, this impact has been significantly reduced.

5. How should I look after my touchscreen on a daily basis?

You can follow these recommendations: clean the screen regularly, use a screen protector, handle the device gently, update software and drivers, optimise power settings, control temperature and humidity, and ensure the device is well ventilated.