Suppose I find a patent (A1) with claims 1, 2 and 3. Claim 2 is dependent from claim 1. If I find a prior reference that rejects claim 1. What happens with claim 2? Is still valid? Should they rearrange that claim?


A dependent claim is ALWAYS valid when its independent claim is valid. However, if an independent claim is invalidated, that DOES NOT ALWAYS necessarily mean that dependent claim is also invalid.

However, the procedure for amending the independent claim by including limitations from the dependent claim(s), and the process of examining the patentability of the amended claim can vary from one country to another.


  • Yes I thought so, I have added the country (USA), could you explain when or how could that dependent claim be rejected? I have in mind these patent. And are you afiliated to invntree? You paste the link and it's not related to the question... – llrs Oct 30 '14 at 12:28

If the document ends in A1 it represents the publication for an application, not a granted patent. If the application is still in the prosecution stage and this prior art was known the the examiner claim 1 would be rejected. The applicant could respond in a number of ways including amending claim to also include the limitations of claim 2 (and canceling claim 2). Or claim 1 could be amended in some other way that gets it past the reference. During prosecution a claim is not invalidated, just objected to and/or rejected. Invalidation is something a judge does in an environment (court) that doesn't allow for amending.

  • Oh the terminology is playing again against me :(. Thanks for refreshing that they still have time to modify their patent application. It sets a new scenario... – llrs Oct 30 '14 at 12:37

As a patent owner, you can leverage in enforcing patent against an infringer and negotiating or maintaining the terms of a license agreement by using the validity or invalidity of a patent claim as the basis.

Once issued, a patent is presumed valid, this is as mandated by the U.S. patent statutes. This means that each claim is presumed valid independently from any other claims. Which also means that even if the independent claim is considered invalid, the dependent claim is still valid and enforceable and would require a separate validity analysis.

  • Could you put an example how the dependent claim is presumed valid independently from other claims? If claim 2 is a specific subset of claim 1, both could be rejected, isn't it? – llrs Oct 30 '14 at 12:32
  • A dependent claim is a narrowing of an independent claim. Claim 1 is is a skateboard, skateboards are old so claim 1 is rejected (or found invalid). Claim 2 says "the apparatus of claim 1 further comprising a jet engine." A skateboard with a jet engine is not old so claim 2 is good. – George White Oct 30 '14 at 15:42
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    George is right. Further, you must analyze the invalidity of each asserted claims separately. To prove the invalidity of the claim, one must persuade that it is most probable that the claim is invalid. One must present prior art that was rejected by the USPTO during the prosecution of the patent with which the prior art invalidates certain claims of the patent. – ShaneParker Nov 3 '14 at 3:33

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