Patent ID: 8599547

Claim:
A protective enclosure for a handheld electronic device having a capacitance sensing interactive control panel comprising: a shell that surrounds and encloses said handheld device when said handheld device is disposed in said shell, said handheld device being a separate unit from said protective enclosure, said handheld device being insertable in and removable from said enclosure by hand, said shell being substantially crush-resistant and impact resistant, said shell having an aperture that is aligned with said capacitance-sensing interactive control panel; a protective membrane that is fixed to said shell over an aperture in said shell so that said protective membrane is recessed with respect to an outer surface of said shell, said protective membrane disposed over said capacitance-sensing interactive control panel of said handheld device when said handheld device is disposed in said enclosure, said protective membrane being sufficiently thin and having a dielectric constant that allows capacitive inputs on a front side of said protective membrane to be transmitted to said capacitance-sensing interactive control panel through said protective membrane; wherein said protective membrane has a dielectric constant in the range of 2.2 to 3.8; wherein said protective membrane is made of engineered thermoplastic selected from the group consisting of thermoplastic polycarbonate, thermoplastic polypropylene, thermoplastic acrylonitrile-butadiene-styrene and thermoplastic compositions containing one or more thereof; wherein said protective membrane has a thickness in the range of 0.003 inches to 0.020 inches; and wherein said protective membrane has matte texture, said texture having a texture depth of 0.0004 to 0.003 inches that reduces the surface area of said protective membrane that is in frictional contact with a user's finger and permits said user's finger to glide smoothly upon the surface of the membrane without sticking.