Patent attributes
A case for a mobile device, including first, second, third, and fourth sides, each with inside and outside surfaces opposite to each other. The inside surfaces of the first and second sides face each other. The inside surface of the third and fourth sides faces each other. The first and second sides are arranged between the third and fourth sides, and the third and fourth sides are arranged between the first and second sides, so that the four sides form at least part of a frame configured to surround a periphery of the mobile device. At least one of the inside surfaces of the first, second, third, and fourth sides includes triangular protrusions that have a triangular cross section and extend toward the inside of the case, so that an apex of each of the triangular protrusions contacts the mobile device when it is arranged inside the case.