Glass thickness and capacitive touch screens

Industrial displays equipped with capacitive touch screens are often prone to mechanical damage and vandalism (e-kiosks, cash registers, game machines, cash machines, vending machines and most outdoor applications). Therefore, the problem of immunity to mechanical damages of such devices becomes extremely important. Except of the housing, touch screens are on the ‘front line’, so there is a high demand for models constructed in a way to increase the mechanical damage endurance. PenMount (AMT’s department that deals with manufacturing of touch screen controllers) came up with a solution that focuses on handling the various thicknesses of the touch screen glass, not only to reduce the probability of braking the cover glass but also to increase the durability of the entire device.

The rule of the thumb is that as the thickness of the cover glass increases, the quality of the touch signal that can be received by the controller decreases. PenMount has overcome technological difficulties to provide customers with the best solutions in this area. Thanks to excellent performance of integrated circuits and use of unique firmware algorithms, AMT improved the sensitivity of the touch signal and S/N ratio and significantly reduced interference susceptibility. Thanks to these changes, it was possible to increase the thicknesses of the supported glass covers.

The combination of the PenMount controller with the AMT capacitive screen and rich software not only provides precise and comfortable touch signal, but also delivers unbeatable operating stability of the device. Currently, there are available three PCAP solutions based on different cover glass thicknes:

Standard firmware

Standard PenMount controller software that supports glass thicknesses of 1.1 mm, 1.8 mm and 2.8 mm glass for 3.5″ to 24″ touch screens.

T-Model

This is a standard T-Model firmware in combination with PM1310 / PM1410 / PM1710 / PM1711 series controllers that can handle glass thicknesses of 6.0 mm for 8.4″ to 24″ touch screens.

Customized firmware

If your application requires 4.0 mm or 5.0 mm glass, you can use a standard controller and customized firmware. For glass thicknesses from 7.0 mm to 15 mm, it is recommended to use a standard controller in combination with a custom PCAP and specially adapted firmware.

Case Study:

PenMount recently cooperated with the client on a kitchen equipment application. The project was based on PenMount PM1310, customized 21.5-inch capacitive sensor and 1.8 mm glass. The customer additionally provided a 5.0 mm thick mirror glass which was laminated to 21.5- inch touch screen and therefore obtaining a total glass thickness of 7.0 mm. The customer was very pleased with the touch control performance on the application.

The above-mentioned case study is an additional inspiration and a confirmation that investing in ruggedized touch solutions is the most appropriate and perspective way.

On our webpage, you will find an up-to-date offer of AMT touch screens and PenMount controllers.If you have any questions, please feel free to contact us.