We have applied for a patent, it is published by 'PATENTSCOPE' of WIPO 7 months ago. It is presently with the International Preliminary Examination Authority (IPEA).

The basis of invention is complementarity of contour patterns on the faces of a pair of discs facing each other to attain specific functions. Now we realize that identical functions can also be attained by 2 more types of contour pattern complementarities on the faces of a pair of the same discs facing each other. Rest of the application is identical. The questions are:

  1. Can 'my own' published application be used against 'my newer application' on the grounds of 'prior-art' - despite that the contour patterns are different?

  2. Won't the 'doctrine of equivalence' defend my patent in a court of law if new inventors try to patent upon those two newer contour patters?

3 Answers 3


Your own prior publications can and will be used against your own later filed patents. There are many many cases where someone's patents were invalidated based upon their own prior publications. However, there are differences on this particular point depending upon where you are seeking patent protection (US vs. India vs. EPO vs. Japan...)

One potential solution is for you to think about how the claims in your original filing can be slightly amended to capture infringing activity covered by your improved idea. The basic approach with this solution is to make a patent claim generic enough to cover the various ways of arranging your apparatus. If your original filing is descriptive enough to support this more generic claim then there is no problem regarding publication because you will have priority associated with your filing date (which is obviously before the publication date).

Now, assuming that you want a patent that specifically claims your new approach. In most countries you will have to be able to justify how your new approach is a significant change from your old approach. (In the US, we call this "nonobviousness", the EPO uses the term "inventive step.") What some folks do is actually rewrite the new application from scratch (using a new patent attorney). That re-writing process tends to instill differences into the application that can additionally be used to distinguish the two processes.

Regarding the Doctrine of Equivalents (DOE). DOE is a doctrine that extends the scope of patent protection beyond what is actually claimed in the patent. Thus, if you claim a solution with up to 10.5% ethane, a court might use the DOE to find that a product with 10.6% ethane also infringes. Over the past 30-years we have seen increasing reluctance of courts to permit DOE claims. However, DOE is a matter of patent enforcement that varies greatly from country to country. In most countries, including the USA, you will not *likely* be allowed to extend your patent coverage to include embodiments that you already knew could not have patented because they were disclosed by the prior art.


Since it is a wipo application so you have to enter in national phases after this. Now if the description of your patent going to be the same then you can file a contiuation application when you go for US national phase filing. Please note that you can file a continuation before the grant of the parent patent. Once your parent patent is granted you can not file continuation after that.

If you do this your patent cannot be cited as prior art.


Since patents are a license to enforce, I think that the owner of the first patent (you?) would have to litigate agains the owner of the second patent (you?)

  • This is not correct. Many products are covered by multiple patents. Each patent owner has a right to enforce their patents against an infringer. However, the patentees do not have any right to sue each other (for holding competing patents). Oct 8, 2012 at 15:38

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