Patent-Misuse Doctrine Law and Legal Definition

Patent misuse doctrine is an equitable rule that a patentee should not be allowed to use a patent to broaden the scope of the patentee's monopoly in restraint of trade or otherwise against the public interest. This doctrine is as an extension of the equitable doctrine of unclean hands and allows a court of equity to refuse to lend its support to enforce of a patent that has been misused. Patent misuse refers to specific types of prohibited behavior engaged in by the owner of the patent rights. It is a affirmative defense used in patent litigation when a defendant has been accused to have infringed a patent. For example, using a patent to restrain competition from an unpatented product or process, or employing the patent beyond its life span to exclude others from gaining commercial advantages by using the product or process. The effect of patent misuse is the loss of patent protection.