11.3.2.3.6-2 Dimensions and Separation of Touch Zones

To allow for finger size and parallax inaccuracy, for large and medium screen sizes, the dimensions of response areas on touch screens should be in the range between a minimum height and width of 10 mm (0.4 in.) and a maximum height and width of 40 mm (1.5 in.), with a separation distance of between 3 mm (0.1 in.) and 6 mm (0.25 in.).

Additional Information: The optimum touch-sensitive area depends on the application and required accuracy. Touch areas greater than 22 mm (0.9 in.) square do not tend to improve performance. 5908,100