A contactless sensing option can detect user interactions up to 30 mm away from the surface of a touchpad glass. Based upon fully customizable ZyBrid® touch sensors, ZyBrid hover has been designed to assist manufacturers of self-service kiosks in their efforts to reassure customers nervous about touching publicly used surfaces.
ZyBrid hover works in conjunction with Zytronic’s ZXY500 projected capacitive (PCAP) controller, which uses proprietary firmware to 
boost sensitivity levels far beyond what is normally possible. Together with a specially designed touch sensor, this enables a significantly deeper touch-field to be generated. Furthermore, the multi-touch sensor can recognize basic gestures (such as zooms, pinches, and swipes) even when the user is wearing thick gloves. It can also be set to work in standard touch mode, of course, with direct user contact to the surface of the touchscreen.
Most other techniques used to enable a touchscreen to detect an interaction without physical touch rely upon infrared or camera-based touch detection hardware mounted around the front edges of the screen. Such arrangements inevitably create unsightly, protruding bezels, which can harbor pathogens and make the screen difficult to clean effectively. They are also susceptible to “false” or accidental touches, as they will react to any object breaking the IR light beams or coming into view of the camera – such as a sleeve, drop of rain or a falling leaf. Furthermore, intense direct sunlight and dust/debris accumulating on the surface may impede performance or prevent it from working. Projected capacitive or PCAP touch technologies will only respond to a finger (sometimes gloved) or a conductive stylus, so they are far less prone to such performance issues.
From a practical standpoint, Zytronic will advise developers of graphical user interfaces (GUI) to adapt their software to ensure an optimal user experience. This includes tips such as increasing the size of icons to be touched and introducing wider ‘guard bands’ around each active button area. Both will help reduce the risk of accidental touches when interacting with adjacent controls.
“Current PCAP-based contactless technologies typically only support maximum distances of about 10 mm from the surface of the screen and generally cannot detect a touch from a gloved hand,” explains Dr. Andrew Morrison, Technical Director at Zytronic. “This is because they rely on either ITO or a metal mesh to create the projected capacitive matrix on the rear of the sensor – and both have a relatively low conductivity. In contrast, for ZyBrid hover, we deposit a proprietary copper matrix pattern on the rear of our touch sensors, and together with our latest ZXY500™ controller and custom firmware, allows us to detect changes in the transferred energy from further than ever before. This means that touch events can be registered at least 30mm away from the surface of the screen, even from a gloved hand.”
Zytronic Displays Ltd., Whiteley Road, Blaydon on Tyne, Tyne & Wear, NE21 5NJ, UK Tel: +44 (0) 191 414 5511, https://zytronic.co.uk/
