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How to do a Prior Art Search

How to do a Prior Art Search Article. Prior Art and Patentability Searching Basics. Welcome! We are a Patents Office. We offer affordable professional patent services – by a USPTO Registered Patent Practitioner (Patent Agent, Attorney, Lawyer). Contact us to discuss options.

Prior Art and Patentability Searching Basics.

The basics on how to start and conduct a prior art search by Carson Patents – your patent search firm. Learn patent searching basics.

A basic Patent Search is researching various data sources to determine if there is prior art that discloses your invention. Prior art is existing patents, patent applications, and publications (non-patent literature). It is found around the world. Prior art is those existing documents that are similar to your invention, or describe your invention.

Things you will need to do a search.

You will need three things for input into the search engines to do a patenting prior art search. You will need the following three things:


The place to start a patent search is with the description of the invention. A description of the invention that is just a simple sentence or two is the easiest to work with. A concise description is easier to work with. This is because, what you will need for actual searching in databases is just the right few keywords and the right classification(s) for the invention. You are looking to locate all the existing products and processes that are the most similar to your invention.


The description is used to develop a good set of keywords to use for searching. The best keywords to use are those terms and phrases about the invention and its field of use that describe it most accurately and completely. A good concise description will be simpler to use. The concise description likely already has many if not all of the keywords that you will need to start a search.


The final piece of input for a patent search is the classification. The classification system to use is the CPC Scheme (find it on the USPTO website). The CPC is the Cooperative Patent Classification system. The CPC (like all classification systems) categorizes inventions into classes. The idea is that all the other inventions that are like your invention will be in the same class(es). Searching by class is essential to a complete patent search.

Important TIP: If you don’t know or can’t find the class(es) for your invention, one place to start is the class(es) of the patents that you find with keyword searching. After you find a patent similar to your invention, you can use that patents classification as a starting point for your invention.

You should search the following data sources (places), at a minimum. The more places searched the more complete the search. However, the following list of sources will give you a good start. And, quite likely, more prior art (existing stuff like yours) than you were expecting.

  • United States Patent and Trademark Office (USPTO) –
  • European Patent Office (EPO) –
  • World Intellectual Property Organization (WIPO) –
  • Google Patents –

Steps to searching.

The following Three Steps are the basic process of searching for Prior Art and conducting the database search.

Step 1: Step one is to use the keywords to search. The easiest databases to search in are the Espacenet, and Google Patents databases. You are looking for products or processes that are similar to or describe your invention.

Step 2: After the initial search. Step two is to review the results. Assess, Evaluate, Refine keywords and classification(s) to narrow the results. You are looking for only those products or processes that are the most similar to your invention. The more specific the keywords are the better the results will be.

Step 3: Use refined keywords and classification(s) for Full Search of all data sources to be searched. An exhaustive search would include databases from many countries in many languages all over the planet. At a minimum, the databases available at the USPTO, the EPO, WIPO, and Google Patents should be searched.

What you must try to find.

Try to find out whether the invention is described in the prior art. Is your invention already available, or described in the existing patents, patent applications, and publications (prior art) around the world?

Important TIP. Proper searching greatly enhances good patent specification writing. Searching guides good claim writing by finding existing similar claims. Better claims are easier to allow, and improve the protection the patent provides for your invention. And, importantly, are easier to prosecute. Thus, proper searching can reduce or eliminate potential rejections and objections. Thus, proper searching can save you money.

Patent Practitioner Help Recommended.

The United States has specific criteria for whether a patent, patent application, or other disclosure may be relevant prior art to a patent application filed at the US Patent Office.  For example, in certain circumstances an earlier disclosure by the same inventor may be excusable.  In other circumstances, an application filed earlier, but published later than your application, may be cited against your application.  If you are unsure, we provide a Free Initial ConsultationContact Carson Patents to start the steps to patent for your invention.

We highly recommend that you contact a patent search firm with a USPTO Registered Patent Practitioner for expert help.

Disclaimer: Nothing in this article constitutes legal advice.

Prior art searching and patentability determinations are time consuming and complex tasks. Importantly, all patents, patent applications, and non patent literature (everything in academia and the internet) from around the world need to be examined and considered in an exhaustive search. Further, the expert search needs to include any and all other related fields of potential use that may be applicable with the idea or invention.

How to do a Prior Art Search - Carson Patents

How to start and do a prior art search – Patent Searching Basics. Hire Carson Patents – your patents prior art search firm.

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