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How to Conduct a Patent Search

By: Christopher Heer, Annette Latoszewska | Last updated: November 25, 2020

A patent search can be the difference between a profitable and a wasted investment into the patenting or commercialization of an invention. Proceeding to do either without the benefit of a search can mean investing significant time, money and energy into the process only to be denied a patent, or worse, be sued for infringing someone else’s patent.

A patent search may be conducted with the goal of assessing the patent eligibility of an invention – i.e. whether the invention is new and inventive – and/or with the goal of determining whether practicing an invention may infringe an existing patent (whether you have freedom to operate). For example, where your invention is an improvement on an existing product, you may not be legally entitled to make, use or sell the component existing product. If this is the case, you will need to obtain permission, in the form of a licence or assignment of the patent, to practice your invention.

The potential liability and considerable expense associated with a patent infringement suit or a rejected patent application, respectively, make investing in a patent search very valuable. Further, understanding the prior art landscape before filing an application can help an applicant anticipate potential objections and hurdles to registration, and prepare an application with the greatest chance of success.

Patent searches are commonly conducted by patent lawyers with experience filtering through hundreds if not thousands of documents to identify those most relevant to the invention in issue and analyzing these documents to provide an opinion on the patentability of the invention, and/or the inventor’s freedom to operate. An inventor or applicant can, however, also conduct their own patent search. The inventor or applicant has the advantage of often being more familiar with the art to which the invention relates, including having an understanding of the common knowledge held by persons skilled in the art and the relevant terminology. This article will provide some helpful guidance for inventors and applicants performing their own patent searches.

Do-It-Yourself Patent Searching

A great starting point for any patent search is Google Patents, which is generally easy to navigate, retrieves patents and published patent applications from across the world, and allows filtering of search results on the basis of relevant dates, classification, and ownership among other variables. How you use these tools will depend on the goal of your search. If you’re assessing freedom to operate, you can use the date filter to limit your search to those patents which would still be in effect today – remember that a patent in Canada, for example, has a limited term of 20 years from the date of filing. If you’re assessing patentability, however, all patents and applications will be potentially relevant.

Searching based on the Cooperative Patent Classification (CPC) can also be particularly useful. The CPC is a patent classification system with over 250,000 categories. The use of CPC categories in addition to keyword searching helps retrieve results most relevant to the invention and the art to which it is directed. This is particularly useful when the keywords searched are in common use across multiple industries and subject areas. Relevant CPC categories can be identified before beginning your search or may be more easily identified based on a review of the results returned by a preliminary search. Further, when selecting keywords for your search, be sure to include synonymous terms. Synonymous keywords can be searched simultaneously on the Google Patents platform. Consider, too, the different forms a keyword may take. For example, if searching for prior art in the field of beverage carbonation, keywords carbonated, carbonation, and carbonate may all return relevant results. These related terms can be captured through the use of the search term “carbonat*”. The asterisk results in the return of any patents and applications which include terms beginning with “carbonat”.

In conducting your patent search, you should be looking for elements of your invention in patents and published patent applications around the world, as well as, in the case of a patentability assessment, in any other publicly available document. If you identify elements of your invention in any of these documents, a patent application for your invention may be subject to a rejection on the basis of novelty or obviousness and practicing your invention may result in liability for infringement.

If all elements of your invention are found in a single piece of prior art (prior art describes the patents, applications, other documents and products which would predate your application for a patent), you can anticipate a rejection on grounds of novelty. If the elements of your invention are scattered among multiple documents, you can anticipate a rejection on grounds of obviousness if it would be obvious to combine what is disclosed in each of these documents to produce the invention. To be liable to a patent owner for patent infringement, one or more elements of your invention must come within a claim of an in-force patent. If your invention does not include all of the essential elements of any claim, your manufacture, use and sale of the invention should not infringe that particular patent. This assessment, however, is complex and best reserved for an experienced patent practitioner given the risk associated with getting it wrong.

If the goal of your search is to determine the patentability of your invention, note that the scope of your search is necessarily much broader. You will need to search the state of the art as a whole – that is, all publicly available documents directed to the art to which the invention relates. Any publication anywhere in the world can render your invention ineligible for patent protection if it shows the invention is not new or is obvious. This includes scientific articles, YouTube videos, social media posts, books, products, etc.

Finally, recall that patent applications are not normally published immediately upon filing. For this reason, even the most comprehensive search can fail to return all relevant prior art. This is an unavoidable consequence of the patent system and a risk inherent in applying for a patent. In terms of patent infringement, you cannot be held liable for infringing a patent that has only been applied for and is unpublished. If, however, the application is eventually granted, the owner of the patent can seek legal recourse against you for your activities between the date of publication and the date the patent was granted if these activities were such as would infringe the patent.

Should I Use a Patent Lawyer to Conduct the Search?

Although inventors may have the benefit of common knowledge in the art and a familiarity with industry terminology, a patent practitioner has the benefit of significant experience conducting patent searches for a wide variety of inventions and perspective, gained with every prosecuted patent application, as to what constitutes damaging prior art. In terms of freedom to operate, patent practitioners have experience dealing with issues of claim construction, meaning the determination of what is meant by the claims in a patent, and by extension determining whether a given invention is caught by the claims.

Note, however, that even a patent search conducted by an experienced patent practitioner cannot guarantee an application will be allowed by a patent office. Ultimately, the decision is typically that of the patent examiner (subject to rights of appeal). Applicants not prepared to invest in a full patent search by a patent practitioner should consider consulting a patent lawyer after having completed the search themselves. The patent lawyer may be engaged to apply their specialized knowledge and experience to the review and analysis of the references identified by the applicant and to assess, on the basis of these references, the likely patentability of the invention or the applicant’s freedom to operate. The cost of this limited scope service will depend on the number of documents the applicant seeks to have reviewed.

In conclusion, any amount of searching and analysis prior to filing a patent application or practicing an invention tends to be a worthwhile investment to make. These searches yield valuable insights into the state of the art and the future prosecution of an application for a patent and may also help identify and avoid significant legal risks and liabilities.

If you would like our help conducting a patent search for your invention, or reviewing the results of your own patent search, contact us now for a confidential and complimentary initial telephone appointment with a member of our team.