Tailored-made touch panels

What connects buying a public transportation ticket, ordering a meal in fast food restaurant, and receiving or dispatching of a package? You can do all of these activities on your own using a device with a touch screen which became a “mediator” in communication between humans and machines.

The module consists of two essential components – a display and a touch screen. Many suppliers offer complete solutions – as standard units that can be instantly mounted in the device. However, there is a worth noticing alternative – a personalized module with attuned parameters and outstanding design. Then, what you should know about the customization of touch screens? Here you can find some tips.

Display

The LCD-TFTs are still the most popular displays in touch applications. There are a few parameters determined by the operating conditions in specific locations, e.g., brightness which must correspond with ambient light intensity. In the case of outdoor applications, another important feature is operating temperature – displays operating in a moderate climate must function properly during hot summer as well as cold winter. Moreover, we advise choosing displays with hiTNI technology for devices located in sunny spots. The solar radiation (which can heat the surface of displays to about 100°C) affects liquid crystals – they lose their features, block the flow of light, and finally turn black. The hiTNI technology prevents the temporary damages of LCDs. 

Touch sensor

There are a few touch technologies on the market, e.g., capacitive solutions. The functioning of capacitive touch sensors is based on the distortion of the electrostatic field caused by a touch of the electrical conductors (as our fingers). This technology is more and more popular among our customers (in the heavy industry too). There are a few functionalities that make them a top choice as water rejection and palm rejection. They not only detect the presence of water or object on the module’s surface but also limit their impact on the functioning of the device. The capacitive touch sensors allow multi-touch operation so multiple points of touch can be accurately tracked at the same time.

Cover glass

One of the forms of module preservation is the application of hardened cover glass (of 0.55 up to 15 mm thickness) which prevents mechanical damages. If you want to distinguish your touch screen, you can do this by customizing the cover glass. There are a few potential features as the non-standard form (as you can cut out various shapes in cover glass) or the additional button (as you can cut out discretionary openings in cover glass). Moreover, due to the constant development of printing technologies, you can paint it in various ways. It can be not only simple logotypes but also photorealistic graphics.

Coatings

There are also a few kinds of coatings that increase the user experience such as: anti-glare (AG) and anti-reflective (AR) coatings which reduce reflections, anti-fingerprint (AF) coating which prevents the adhering of various contaminations, and anti-shatter (AS) coating which prevents the spreading of glass splinters while the module is smashed. There is also another type of coatings that might be highly recommended in the time of coronavirus pandemic – anti-microbial (AM) coatings which effectiveness has been estimated up to 99.9%.

It is worth underlining that even if you apply all of these coatings on a single module, they not affect the functioning of the device.

Cleanroom

What then can affect the functioning of the devices? Well, any contaminations that may accidentally get stuck between the “layers” of the modules. That is why the assemblage of touch screens should take place in the cleanest production conditions that are feasible only in cleanrooms. These facilities are equipped with the air handlers that purify the air with a set of HEPA or ULPA filters and provide the proper air conditioning. We can offer such production conditions – a few weeks ago, the first modules left our new 45 m² cleanroom (with ten workstations).

The number of airborne particles in a particular volume of air (e.g., one cubic meter) determines the cleanliness level of cleanrooms. The most commonly used classification of cleanrooms is the nine-tier rating defined by ISO standard 14644-1. Our cleanroom meets the standards of ISO class 6 (the maximal concentrations of airborne particles in ISO class 6 are following: ≥5µm – 293, ≥1µm – 8 320, ≥0.5µm – 35 200, ≥0.3µm – 102 000, ≥0.2µm – 237 000, ≥0.1µm – 1 000 000; learn more about classifications of cleanrooms – here.)

Optical bonding

As important as clean production conditions are also proper methods of displays bonding with touch screens (cover glass and/or coatings too). Today, you can gain the best effect with optical bonding technology. In this method, transparent glue or foil (stiffened by UV light) bonds all the components, so there is no air between any “layer” of the module. The optical bonding improves the picture quality by reducing the light refraction and eliminating foggings (the module is air-tight so no water or dust may settle between the layers) or interferences (the module is perfectly combined so no layer may distort). It also reduces, e.g., Newton’s rings phenomenon (the formation of interference pattern by the reflection of light).

Case study

Let’s imagine that we design a self check-in with a 21.5-inch touch screen. It will be located in the airport’s interiors.

First of all, the essential components – a display and touch sensor in this case combined with a 4-mm cover glass. It prevents the module from unintentional mechanical damages made by passengers (e.g., hit by baggage). The best choice is UniTouch, a product line by Unisystem which, due to universal parameters and added cover glass, can be applied in various devices (like self check-ins).

The touch screens of such interactive kiosks are one of the largest habitats of microorganisms among all the surfaces at the airport, so in this instance, we primally advise applying the anti-microbial (AM) coating to increase the users’ safety. Other coatings, like anti-fingerprint (AF), is just a nice-to-have feature that provides visual cleanliness (by reducing the visibility of fingerprints and other marks and smudges).

The described application is only an exemplary case study. However, due to this theoretical consideration, we can conclude that each project needs an individual approach – we have to analyze the factors that influence not only the device functioning but also the user experience.

If you need a hand with customization of your module – contact us . We are here to help you.