“Hidden public use” is a public use wherein the invention is an item in public use, but whose workings or qualities are not directly revealed to, or understood by, the public. Devices that are available to the public, such as a cell phone or computer, possess valuable unseen or concealed qualities even upon inspection. U.S. courts have held that “hidden public use” prevents patenting when the public knows either how to make or use the claimed invention. Such prior uses preclude a patent because the public enjoys the invention’s benefit by using the product without knowing of, or understanding, its inner workings or mechanisms.