Opposition Search for SEPs

An opposition search is a prior art search aimed at knocking down a patent that has already been granted. The search runs across all the patent claims and looks for disclosures published before the priority date. Findings go into a comprehensive report that challenges the granted claims, supported by an analysis of the prosecution history showing the basis on which the patent was allowed. The output feeds an opposition, a revocation action, or a defensive position in a licensing discussion.

A novelty search looks at an invention before filing and asks whether it is new. An opposition search looks at a patent after grant and asks whether its claims can be defeated. The evidence standard differs: an opposition needs art that reads on specific granted claim language, carries a reliable date before the priority date, and is documented well enough to survive challenge. It also needs the file history, because the arguments that won allowance point to the features an attack has to meet.

Research runs across several kinds of sources: patent databases, non-patent literature, and journals. Patent documents give clean dates and claim language, so they are the fastest route to a close reference. Non-patent sources such as conference papers, technical journals, standards contributions, product manuals, and theses often hold the disclosure an examiner never saw. The prosecution history of the target patent is reviewed alongside the search, since it identifies the basis for the allowance and narrows where to look.

As soon as a competitor patent of concern is granted. Monitoring competitor patenting activity is what surfaces such a patent in the first place, and moving early keeps the widest set of options open, because formal opposition windows at many offices close a fixed period after grant. An early start also leaves time for the slower part of the work, which is the non-patent literature, and for reading the prosecution history to see why the claims were allowed.