I'm interested in a beginners guide on how to invalidate a patent, like searching for prior art, and what to do next, etc.

Hopefully someone can help!


A short version is that U.S. patents are presumed valid when issued. After issue, a patent can be challenged in a handful of different USPTO procedures. Any third party can file to try to initiate one of these actions. The least expensive procedure has a min. $6000 filing fee. Besides that fee and good prior art you will need good lawyering to be sure to put your best data/arguments forward. The patent office can determine some or all of claims are not patentable and the patentee has a chance to amend the claims to make them narrower or otherwise acceptable.

In a patent dispute that makes it to court, an alleged infringer can argue that one or more claims, or the whole patent are invalid. There may be a judgment of invalidity or un-enforcability. In a court proceeding the claims can't be changed.

A few patents have been disclaimed by the patentee after receiving widespread public ridicule. IBM disclaimed its patent for managing a queue of people waiting to go to the bathroom on an airplane.

Of course this site was set up for crowd sourcing the search for good prior art to be used against patent applications. It can certainly be used to try to collect good prior art against issued patents.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.