Defenses

General

In a case of patent infringement, the accused infringer may assert several defenses against the patent holder to argue against the patent infringement claim.  The patent statute describes some of these in 35 USC 282.  Some available and more common defenses include: Non-infringement; Invalidity; Inequitable Conduct; Anti-trust/Patent Misuse; and Laches/Equitable Estoppel.

Non-infringement

Perhaps the most straightforward or commonly used defense is that of non-infringement.  The defendant simply claims that its accused activity does not infringe the patent claims.  Read more detail about what constitutes infringement in our section about patent infringement.

Invalidity

The patent statute provides that once the United States Patent and Trademark Office (USPTO) issues a patent it is presumed to be valid.  However, in the context of a patent infringement lawsuit, defendants have the opportunity to challenge the validity of a previously issued patent.  The defendant can assert that the patent fails to meet the required test of patentability.  A defendant can do so by doing one or more the following:

1. Providing evidence of prior art (previously patented work) that was improperly considered, or not taken into account, when the U.S. Patent and Trademark Office (USPTO) reviewed the patent in an attempt to show that the patented invention was not novel.
2. Providing evidence of prior art which in combination would render the invention obvious to a person having ordinary skill in the relevant field in which the patent is used.
3. Providing evidence that the inventor did not apply for the patent in a timely fashion after making the invention known to the public.

Often in patent infringement actions, one of the parties may request a patent reexamination proceeding at the United States Patent and Trademark Office (USPTO).  A reexamination is a proceeding in which the US Patent and Trademark Office (USPTO) reevaluates the invention and the patent claims, and reassesses the patent’s validity.  The reexamination may result in certain claims being rejected or amended (most often narrowed).  In a patent infringement context, if the reexamination finds the patent to be valid, a defense of patent invalidity is no longer appropriate. 

A defendant may initiate a reexamination during patent litigation and simultaneously request a stay of the patent litigation from the court that is hearing the patent infringement case.

About Our Firm

Protecting your intellectual property rights is a complex business. If you suspect that your product might have been infringed, it may be advisable to rely on the expertise of an experienced IP rights lawyer to protect your rights. The Intellectual Property team at the Law Offices of James Scott Farrin is headed by Attorney Tara J. Williams, a patent attorney with more than 20 years of legal experience. The firm also has a unique contingency based Intellectual Property Department for certain infringement matters. The department’s goal is to assist small-business owners, artists and inventors to protect their creative endeavors when they may not otherwise have the resources necessary to do so. Call 1-866-760-4047, for a free, confidential review of your potential claim – or simply complete the contact form on the side of this page.