I found about the patent too late while searching for eventual patent. The main idea of the patent under question was entirely my own. It was first implemented in a prototype, and then a production facility was setup in Japan. The patent was issued to two other inventors. One ofthem I knew very well and we worked together on the prototype. Unfortunately, He passed away last year. I do not know the other inventor and I could not find any clue about him nor about the Company name mentioned in the patent (neither could my friends in Japan).

I have all the evidence (and I have witnesses abroad, too) to prove that I am the main Inventor of the patent. Who I should contact so that my name is included as an Inventor of the patent:

  • the law firm under the correspondence address?
  • the US Patent Bureau?
  • or third party law firm?

Does it matter if the patent has expired because the fees have not been paid?

  • @jimm101 Jim, This is very similar but different case from that one you provided a very good answer some time ago. I will appreciate if you do the same for this case. Thank you very much in advance.
    – Chezare
    Oct 26, 2017 at 21:49
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    Under US laws, a patent that fails to name all inventors related to of any of the claimed invention may be ruled legally invalid as "fraudulent". In theory, one could petition the US Patent Office to reissue the patent in view of your new information, i.e., that the named inventors were not all of the actual inventors. It would be expensive and time-consuming, and you would need to determine what value you place upon proper recognition of your achievement. MPEP § 1402. Your local patent attorney may assist you.
    – Upnorth
    Oct 27, 2017 at 5:33

1 Answer 1


Correction of named inventors is covered under 35 U.S.C. § 256. If all the parties agree that you should be named, the inventorship could possibly be corrected by a petition (and a fee, most likely) submitted to the USPTO. Otherwise, you may be able to retain a lawyer and sue to have your name added. However, that route would likely end up being rather expensive.

  • In that case, the best way is to contact the Law Firm of the patent to arrange for the agreement of the other party as they have the contact number (I don't). I could cover their fees for the same, and they will have an interest to keep the patent be legal instead of dealing with court defending the other party. Is this approach the best I should try first?
    – Chezare
    Oct 28, 2017 at 22:11
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    @Chezare You may be able to find the owner of the patent using the USPTO Assignment tool. However, if the patent has expired because of unpaid maintenance fees, then it is unlikely that the assignee is concerned about about maintaining its validity (they let it expire, and so it can no longer be used to protect their claim to the invention). In fact, it's entirely possible that they've gone out of business. That said, you can certainly try—I just wouldn't hold out too much hope for cooperation. I'm not even sure if the USPTO will correct an expired patent. Oct 29, 2017 at 16:55
  • The additional information I got by USPTO Assignment Tool regarding contacts is the name of the person for Correspondence with the Law Firm. No other additional contact data (in addition to what has been publish in the patent) were revealed by the USPTO Assignment Tool.
    – Chezare
    Oct 30, 2017 at 22:50

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