Suppose that inventor John holds the current patent and prior art for:


Steve comes along and patents:


Then a manufacturer begins selling




Who is the manufacturer infringing upon, John or Steve?

Who holds the rights to sue the manufacturer for profits, John or Steve?

  • This is some kind of hypothetical scenario, right? Steve patenting A+B when A+B+C is prior art should not occur if that prior art turns up during the examination. Sep 8, 2022 at 19:13

2 Answers 2


One product can easily infringe more than one patent. Settling with or licensing one patent is irrelevant to the second infringement case from an unrelated patent owner.

If one of the patents should not have been granted a strategy could be to license one while constant the validity of the other.

  • “Constant the validity”, should be “contest the validity”.
    – Eric S
    Sep 9, 2022 at 15:41

My guess, and I am not a lawyer, it that both John and Steve can sue the manufacturer for selling A+B+C or A+B+C+D+etc. An interesting question is whether Steve has any rights to sue if the manufacturer takes a license from John. I would guess not, but again I'm not a lawyer. It might be best to wait for a lawyer to answer.

  • 2
    In my view, the manufacturer requires the license from both John and Steve. Having the license from John is like John directly selling A+B+C. Without John having a license from Steve, and licensing both A+B+C and A+B, the manufacturer will have issues with one of the two. Sep 8, 2022 at 19:15
  • @theEuropeist I’d very much encourage you to answer.
    – Eric S
    Sep 8, 2022 at 22:11
  • It was not part of the question. Sep 12, 2022 at 12:41

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