Patents and Patent Defenses

A patent is a federal statutory right that allows an inventor to exclude others from making, using, selling, offering for sale, or importing the patented invention without the inventor’s permission for the limited period specified by the patent statute. If a person or other entity makes, uses, sells, offers for sale, or imports the invention covered by the patent, they have infringed the patent, and the patent owner may bring a lawsuit to seek relief. There are several defenses to allegations of patent infringement available to someone who is sued for patent infringement. Two of the available patent defenses are that the allegedly infringing activity is not an infringement of the patent and that the patent is not valid and cannot be enforced.


A patent consists of one or more claims that define the rights and the extent
of the patent protection. The actual invention that is the subject of the patent
elements that are not eligible for patent protection and thus will not be part
of the patent claims. If the allegedly infringing item is not covered by any
of the patent’s claims, there is no patent infringement. For more information
about patent claims see our other story about patent claims covered in this
month’s newsletter.

Patent Invalidity

There are several technical requirements for a valid patent. If one or more of those requirements has not been properly met, the patent might be found to be invalid. An invalid patent confers no protection and thus cannot be infringed. Although it is presumed that a patent issued by the United States Patent and Trademark Office is valid, if the validity of a patent is challenged either in defense of a patent infringement action or in an original action challenging the validity of a patent, evidence might be produced in court that demonstrates that the patent should never have issued.

A patented invention must be new; thus, a demonstration that the invention was known, used or even already patented before the patent in question was issued might lead a court to conclude that the patent is invalid. A patent also must not be obvious in light of the existing patents and other literature pertaining to the field in which the invention is classified. If a court finds a patented invention to be an obvious extension or evolution of existing inventions in that field, it might invalidate the patent.

The purpose of patent law is to encourage the disclosure of new inventions and technologies. The incentive that patent law provides to inventors to disclose their inventions to others is the right to exclude others from making, using, or selling the invention for the term of the patent. As a condition of that the grant of exclusive right, an inventor’s disclosure must be complete. An inventor is required to disclose enough information to enable another party skilled in the field in which the invention is classified to build the invention. In addition, the inventor must describe the best way to build the invention. For example, if the invention works with copper wires but works much better with fiber optic strands, the inventor must disclose that fact. If a patent is found not to fully enable another to build or make the invention or does not disclose the best mode of making the patented invention, the patent can be found to be invalid.

Leave a Reply