At Zytronic we’re immensely proud of our Projective Capacitive touch technology, and its responsiveness and reliability in the toughest environments is often praised by our customers. Our R&D team work tirelessly to ensure that everything we design and supply – both the hardware (touch sensor and control electronics) and the controllers embedded firmware and our software interfaces are thoroughly tested and meet the highest international standards . However, if you want to get the best possible performance from your new Zytronic touch screen a very important point to remember is that good integration is key!
Integrated correctly, touch screens will have fast and accurate responses that will wow your customer, but poor integration can cause a multitude of problems and the performance of the touchscreen will be diminished, and you’ll be left with unhappy users.
The performance of PCT™ touch sensors are drastically effected by their incorporation into a new system, so…
How should you integrate the touch sensor?
You’ve probably already chosen your LCD, and assisted by Zytronic Sales staff you probably have a custom designed, sample sensor whose active area meets your requirements, and the right type of touch controller for your application (single, dual or full multitouch).
Firstly, a suitable air gap is a must.
All LCD’s produce electronic “noise” or EMI, (some more than others) and an air gap between the front of the display and the rear of the touch sensor is necessary to prevent excessive noise from interfering with a Projected Capacitive touch sensors operation. The air gap can be achieved using a suitable gasket our recommendations for gasket thicknesses can be found below.
| Sensor Size | Gasket thickness |
| 5-22” | 3mm |
| 22-32” | 4mm |
| 32-46” | 6mm |
| 46-65” | 8mm |
| 65-85” | 10mm |
Testing before final integration is paramount, especially if you are working with a particularly noisy LCD. Modern LCD monitors are generally quieter and the guideline gasket thicknesses (air gap) above could be reduced if you test and find the optimum air gap.
Choosing your Gasket
The type of gasket needed for good integration is dependent on your application:
- For horizontal applications such as touch tables, a low performance non-conductive gasket can be used.
- For permanent vertical applications or where the weight of the sensor is to be held in place by the gasket, such as bezel-less digital signage or gaming applications, a higher performance, double sided, non-conductive gasket should be used (and consideration should be given to a “lip” along the lower edge of the monitor, to support larger, heavier touch screens).
Once you have your suitable gasket you can apply it as per the manufacturers guidelines, being sure to carefully align your LCD display area to the Zytronic sensors active area.
*If you need help choosing a suitable gasket please contact us and we’ll happily point you in the right direction
Integrating the Zytronic controller
The position of the controller in relation to the touch sensor is very important.
The controller should be positioned so that all of the touch sensors flat flexible cables can comfortably reach the ZIF connectors on the controller.
Key points,
- Keep the flat flexible cables away from any metal work, other cables or PCB’s, that can rub and damage the cables, or induce EMI into the cables,
- Take care with the flat flexible cables, follow the minimum bend radius guidelines in our User Manuals and Instructional Videos, and remember they can be folded but not creased, and they should not be pulled tightly (stressing the joint to the touch sensor).
For best results the controller should be mounted at least 5mm above any metalwork. To do this we recommend mounting the controller using metal stand-off pins or double sided adhesive gasket pads. We also strongly recommend that the controller is grounded to the LCD monitor metal chassis (which in turn should be grounded to earth) using a low impedance ground cable (this is particularly important for anyone mounting their controller with gasket pads)
Using a bezel
If you’ve chosen to mount your touch sensor into a bezel it’s important to remember that they can also have an effect on touch sensor performance, especially if it is metal.
To ensure the best performance when using a metal bezel we recommend
- Using a 3mm spacing non-conductive gasket between the front of the sensor and rear of the bezel
- Metal bezels should be grounded to a common point with the metal chassis, LCD and controller
- Ensure that the bezel has been designed to that it doesn’t encroach upon the LCD viewing area, ideally leaving a minimum space of 5mm so that any User Interface (UI) icons in the corners of the touchscreen can still be easily pressed (and if you’re using the “side swipe” flick gestures in later versions of Windows, you may need to increase this)
- If your application is outdoors the spacing gasket should be able to provide a watertight seal, and ensure that the bezel has been designed with “run-off” channels, so water doesn’t collect and pool on the touch screen.
For examples for good integration practice, check out our great series of instructional videos:
Do’s and Don’ts of integration
Do make sure you have a suitable air gap
Don’t forget to match your LCD viewing area with the touch sensor’s active area
Do choose a suitable gasket
Don’t cross your wires! Flexible cables should be kept away from other cables and metal work
Do space your controller correctly and ground to a common point earth
Don’t hesitate to contact Zytronic when designing your touch system for helpful tips and guidance
By follow our recommendations, your Zytronic touch sensors should function at optimum performance levels. For further help on integrating your Zytronic touch sensor, please download our User Manuals, or contact us directly and we’ll be happy to help.
