New touchscreen sensor assembly for harsh applications

Engineer Live News Desk

TouchNetix has introduced Chrominance, a sensor assembly for touchscreen displays which sets new benchmarks for performance, reliability and ease of system installation in industrial, medical, transportation and military applications, and in any type of harsh or hazardous environment.

The Chrominance sensor assemblies, which are based on TouchNetix’ aXiom series touchscreen IC for use in challenging applications, feature a high signal-to-noise ratio (SNR) of >80dB. The Chrominance product’s low noise floor and ultra-high sensitivity enable the recovery of capacitive touch signals even when high levels of EMI from sources such as high-voltage cabling, electric motors or wireless communications are coupled to the Chrominance sensor element via the user’s finger.

This means that industrial equipment OEMs which integrate Chrominance-based touchscreen displays into their products can provide reliable, out-of-the-box operation to their end users, with no need for site-specific touch-sensor tuning and configuration. Touchscreen tuning is a time-consuming and difficult process which industrial users must perform when installing conventional capacitive touchscreen assemblies.

Because of the Chrominance modules’ high immunity to conducted and radiated interference – they are qualified to Class A according to the EN61000 standard Parts 4-6, 4-4 and 4-3 – they also maintain reliable performance in harsh operating conditions which often cause conventional displays to fail to recognise touches, or to report false touches.

The Chrominance assemblies are a range of standard touchscreen sensor modules for displays ranging in size from 4.3” to 24” (diagonal). Evaluation kits are available immediately for 12.1”, 15.6” and 21.5” displays.

A Chrominance module is supplied as a 0.7mm glass/ITO sensor hot-bonded to an FPC tail and a TouchNetix aXiom controller board. TouchNetix can bond the module to a standard 3mm cover glass at the customer’s request.

TouchNetix provides reference driver code for the Windows® and Linux® operating systems, and for real-time operating systems used in embedded computing environments.
Wide range of use cases

The Chrominance touch sensor’s high sensitivity means that it supports operation through a thick lens, including glass up to 10mm thick. Gain settings which are programmable per node mean that it can offer uniform touch sensitivity through a ‘3D’ or curved lens which has variable thickness across the touch surface. The Chrominance system also recognises touches by a user wearing thick gloves.

Its capacitive sensing technology also works very well in the presence of moisture and liquids, making it suitable for use in outdoor, medical or marine equipment.
It provides full 16-bit XY mapping of up to 10 concurrent touches. Without using additional electrodes, it also supports:

  • Proximity functionality, for instance to wake up a dark display when the user’s hand approaches the display
  • Hover sensing, reliably and accurately sensing the user’s finger at a distance from the screen of as much as 5cm
  • Concurrent force sensing
  • Low latency haptic feedback control

Chris Ard, Managing Director of TouchNetix, said: ‘TouchNetix has achieved a strong reputation for supplying robust, high-performance touch-sensor assemblies with its earlier Brilliance and Luminance products. Now with Chrominance we have taken full advantage of the unique capabilities of the aXiom touchscreen IC, developed here at TouchNetix, to produce the world’s best touchscreen performance and reliability for any harsh or hazardous application.’