It happens often that patent claims have as broad a scope as they can get away with. However, I have heard that, if your invention can be in general described by an independent claim of a third-party patent, but is implemented using a specific technique that is not protected by that claim, then it can be patented. Is this true?

Further, if one implements such an invention with aforesaid non-protected method, but does not patent it, can one be sued because of infringing on the broader claim of the third-party patent?

For example, let's say that an imaginary patent claims a self-driving car with help of a set of camera sensors, and nothing more specific. If I invent a special algorithm for processing the images of the cameras in order to implement a self-driving car, am I infringing on that claim?

1 Answer 1


You can indeed get a patent for a novel refinement or improvement of an already patented idea. However, while gaining a patent means you can prevent someone from implementing the idea claimed in your patent, it doesn't mean that you somehow now circumvent existing patents. In your example, the fact that you invent a special algorithm for processing the images from the self-driving car's cameras doesn't keep you from infringing on the broader existing patent.

There can be value in patenting your refinement even if you don't have freedom-to-operate. The refinement may be of value to the original patent holder so you can potentially license it to them. It might be used as a bargaining chip to negotiate a licensing deal to allow use of the original patent.

If this question isn't hypothetical then I highly recommend you consult with an actual patent attorney on questions of freedom-to-operate and not rely on advice from internet sites.

  • Let's say that the scope of claim A is very broad and that it cannot be implemented by a person skilled in the art without an additional ingredient B (an example of which might be present in the description of the patent or in a dependent claim). Furthermore, let's say that I have invented an ingredient C (different than B) that in combination with A would make the invention work. Could I file an appeal to force the extra feature B to be included in the main claim A of the original patent, so that I can circumvent it using C? Nov 22, 2018 at 16:13
  • @BrysonofHeraclea You infringe a patent if you only infringe a single claim. Of course you could argue that the invention isn't valid because it isn't enabled, but in reality, you can be sued for infringing a single claim. You can fight the suit in court and have a chance at winning if the claim isn't sufficiently enabled, but really its hard and jurors are in general lay people so don't expect precision in the verdict. I am not a lawyer so if this is important you really need to consult with one.
    – Eric S
    Nov 22, 2018 at 17:31
  • You mean, infringement happens when you only infringe a single independent claim, not just any claim, right? (Are you also infringing, if there is an overlap with a dependent claim but not a 100% overlap with an independent claim?) Nov 23, 2018 at 12:14
  • A dependent claim includes all the elements of the independent claim it references. You really need to run these questions past an attorney with the specific patent specified to get an authoritative answer.
    – Eric S
    Nov 23, 2018 at 15:31

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