Critics of the U.S. patent system say that it too often rewards ideas that are obvious and which rightly belong in the public domain. Supporters, on the other hand, argue that inventors' ideas must be protected.
At right is a diagram illustrating one idea that has won such protection: "Method of excercising a cat." This concept--using a handheld device to manipulate a laser beam that can "amuse and exercise" a feline--is protected by U.S. Patent No. 5,443,036.
This diagram illustrates a cutting cylinder that can be used to create such a sandwich, which can then be stored for "extended periods of time for use in lunch box type of situations." The idea is protected by U.S. Patent No. 6,004,596.
This branch-shaped toy is intended to amuse a dog or other pet. It can be made of rubber, plastic or wood, and a scent can be added. It's protected by U.S. Patent No. 6,360,693.