An invalidity search, or a patent validity search, determines how viable an invalidity defense will be during a possible patent infringement lawsuit by assessing the strengths of a patent claim. Such searches attempt to invalidate or determine the validity of a patent you are looking to enforce. Invalidity searches are important as the Patent Office sometimes makes mistakes and patents can be issued in error. During the licensing phase, a review can show the strength of a granted patent.

Items Needed for a Patent Invalidity Search

With only 12 hours allocated per case to conduct prior art searches, confirm you have these important items:

  • Patent number
  • Specific claims you want to invalidate
  • Target priority date
  • Previous prior art not included with the original patent

When Is a Patent Invalidity Search Needed?

An invalidity search is warranted in the following situations:

  • After receiving a patent infringement complaint from patent owner.
  • After receiving a cease & desist.
  • Prior to enforcing patents of your own.
  • Any America Invents Act proceeding.
  • Confirming validity of a patent before buying or selling.

Determining if a patent can overcome validity claims will assist during negotiations.

When Prior Art Can Invalidate a Patent

While each country has different laws related to the invalidation of patents, there are some common things that any prior art search will be looking for:

  • Publication before the patent priority date
  • Sale of the invention
  • Public knowledge or awareness of the invention
  • Public use of the invention

Prior Art Resources

Sources to consider when looking for prior art include:

  • Physical products
  • Other patents and applications
  • Journals, books, printed literature and Internet publications
  • Proof of public use or sale

Patent art collections are known for being accessible and extensively organized. Over 90 percent of patents can be found by searching the offices of the USPTO, EPO, PCT, and JPO. Different prior art resources may require individualized types of searches.

Getting Started

Challenging novelty or inventive steps requires familiarity with prior art, including all items publicly available worldwide prior to the filing or priority date of the invention application.

  • Note any acknowledged prior art or prior knowledge documents, these are usually found in opening paragraphs.
  • Don't duplicate a search already documented in the application.
  • Ignore priority date if challenging validity.

Case Study: Inventive vs Novelty Step

Image a patent that includes the following claims:

  • A tool featuring a cutting edge supported by metal A.
  • The tool mentioned in claim 1 as a knife.
  • The tool mentioned in claim 1 as a pair of scissors.
  • The tools mentioned in previous claims but including metals B, C, and D.

Upon doing a search, you find the following:

  • Prior art is not mentioned, and the Patent Office search found nothing.
  • Two searches were completed for cutting tools made of metal A and metals B, C, or D.
  • Two published documents found prior to patent filing date. Document 1 describes scissors with a reinforced cutting edge made of metals A, B, C, and D. Document 2 describes a wear-resistant item made of metals A, B, C, D, and E; however, cutting tools are not mentioned.

Based on your findings, you reach the following novelty conclusions:

  • For claims 1 and 3: Document 1 includes all features of Claims 1 and 3, negating the novelty claim for both.
  • For claims 2 and 4: No inventions found with all of the features of Claim 2 or 4.

You also make the following findings regarding inventiveness:

  • In this case, "a person skilled in the art" would be a manufacturer or designer of cutting tools.
  • If such a person were looking to decrease wear on knives and read document 1, he could use the instructions outlined in the document talking about scissors and apply them to knives, making Claim 2 obvious.
  • That same person would logically utilize the alloy described in Document 2, making Claim 4 also obvious.

Documents are not combined in the findings showing there is no inventive step. Searcher is not looking to build a case, simply locate documents an attorney may use to build one. Searcher needs to know what to look for in determining areas to search.

To prove invalidity, you should be able to produce an individual document that illustrates a lack of novelty. If that is not available, seek out most recent prior art to show the lack of an inventive step.

If you need help with an invalidity search, you can post your legal need on UpCounsel's marketplace. UpCounsel accepts only the top 5 percent of lawyers to its site. Lawyers on UpCounsel come from law schools such as Harvard Law and Yale Law and average 14 years of legal experience, including work with or on behalf of companies like Google, Menlo Ventures, and Airbnb.