US Patent 9432491 Waterproof structure

A waterproof structure includes a casing including a first case member having a first facing surface, and a second case member having a second facing surface. A water repellent slit is provided on at least either one of the first and second facing surfaces, extends in one direction perpendicular to a direction of liquid droplet ingress, and has unidirectional fine recesses and protrusions that make water repellency anisotropic.