Suppose a patent application is filed, claiming a method+device that solves some problem. In the patent text it is written that the method can solve A & B, but it explicitly mentions that it cannot solve C. A device is claimed that implements the method. The claim is however written too generic, and nothing is mentioned about the fact that C cannot be solved.

Suppose I invented a new different method, that actually can solve C. I implement it in the same type of device with similar steps as mentioned in the claim of the previous patent. So the claim of the previous patent may block my new patent, as my new invention is (strictly speaking) covered by the claim of the other patent.

Is it possible to successfully obtain a patent on my new invention? Can I for instance refer to the patent text of the previous application and point out that it explicitly mentions that it cannot solve C? How to deal with this?

2 Answers 2


First - Patent applications are not primary judged by the problem they solve, but how they solve it. You invent one way to capture energy from the Sun's rays, and I do to. Both solve the same problem but from what I have written we have no idea if the structures or steps taken have any correspondence.

Second - a claim is going to pin down what the apparatus is - it might also say something like - "for towing cars" but that is just an intended use, not a limitation. And no one would ever write, "but it is horrible for towing boats."

Last - Yes you can get a patent for an invention that it turns out you can't actually make because your invention is a clever optimization or special case of a claim someone already has patented. You have something new, but it falls under something older and patented. I patent a knife and you patent a jack knife. If my claims are drafted well, your jack knife is still a knife as far as my claims go, and you are not free and clear to make it.

Or your invention has a clever part that you get a patent on and also many boring parts (to you) that someone else has a patent on.

  • Thanks for the answer. Really appreciated. I understand that, but the fact that in the patent text it is explicitly mentioned that it cannot solve C does not help me?
    – Henk
    Nov 25, 2014 at 9:29
  • It can help. If your invention has structural commonality with the prior art refernce, it may be cited against you as making your thing obvious. As part of your argument in response, you point out that you can do something the previous invention can't do.
    – George White
    Nov 25, 2014 at 17:01
  • I think it would be unusual to see "explicitly mentions that it cannot solve C" in the description and not in the claims. If this exclusion was in the claims, this would be a red flag to me, as it is probably tacked in to avoid infringement. Sometimes you read some really obtuse claims with double negatives to get the exclusion in there.
    – BobT
    Dec 26, 2014 at 9:34
  • Another possible reason is there is some element "D" such that A B C D are infringing, but A B D are not and C D are not, the inventor can later file a different patent for C D. For example D might be a prior 2axis navigation scheme, while A,B are your north south sensor invention , which also work just as well, C, in east west (but can't do both at once, if they could they would infringe)
    – BobT
    Dec 26, 2014 at 9:43

It is possible to obtain a patent on your new invention as long as that new invention of yours is totally different from the previous inventions that you have. Show how it works to show that it is different from all your previous inventions.

  • Something does not need to be "totally different" from everything else. It needs to be new, non-obvious from what has been done before, and it needs to be useful.
    – George White
    Nov 25, 2014 at 6:55

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