Kiosk Solutions Jun-Jul 2017 | Page 42

touchscreen technology
with the protective cover glass that ’ s often fitted to kiosks and other touchscreens used in public places . One approach is a system based on a measurement of the surface area of an applied touch , which changes the measured capacitive signal levels at the relative touch location on the sensor . This eliminates the need for a piezo-electric or other layers on the glass to measure applied force or pressure , and means that the technology can even be used on thick , rigid and vandal resistant toughened glass surfaces .
Improved immunity to EMI
Electro-magnetic interference ( EMI ) is often an issue for touchscreen systems placed into industrial environments . Similarly , touchscreens deployed in areas where the power supply is inconsistent or not well regulated will also be affected by transient interference coming up the power cable from the mains supply . This can create problems for touchscreens and their control electronics in terms of identifying the signal , or touch , from the surrounding noise , i . e . decreasing the signal-to-noise ratio and thereby impairing the identification of true touch events , which will impact on operation .
Major improvements to the electronic design and touch detection firmware employed by the touch controller are ensuring that signal integrity is maintained at a high level . P-CAP touch technologies such as proprietary Projected Capacitive Technology ( PCT ) have an X-Y matrix of micro-fine capacitors , embedded within a laminated glass substrate , and use frequency modulation to detect minute capacitance changes within the conductive tracks . One way to combat EMI is to implement a ‘ smart ’ frequency scanning function in the touch controller . The operating frequency moves dynamically between 1.3MHz and 2.5MHz in order to avoid detected environmental ‘ noise ’ that would otherwise prevent the detection of touch events .
Glass improvements Materials technology is leading to glass that is thin and light yet very tough indeed . The latest development is to include anti-microbial elements in the glass , ensuring that any bacteria on the glass surface die away rather than multiply . Antimicrobial Corning Gorilla Glass , the first antimicrobial cover glass registered with the U . S . Environmental Protection Agency ( EPA ), is a safe and non-toxic material for display cover glass . This glass contains an ionic silver component that serves as an agent that greatly reduces the ability of bacteria to proliferate , ultimately helping to keep the glass clean .
Furthermore , it ’ s tough and scratch resistant , so is unlikely to develop cracks in which bacteria can multiply . The anti-microbial agent does not affect the excellent optical clarity of the glass . Laminating a chemically strengthened glass cover layer with a thicker , thermally tempered rear glass , can create an incredibly impact resistant sensor for external or unattended touch screen applications where added rigidity and impact resistance may be needed .
Combining the benefits of damage resistance , optical clarity and touch sensitivity , the glass is formulated with antimicrobial properties to help keep touch surfaces clean of stain and odour causing bacteria , with a performance that will last the lifetime of the display .
42 KIOSK solutions