An Inventor’s Guide to Understanding Prior Art

November 03rd, 2020 ‧ 6 min read

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If you have been reading any number of articles on this website or following our social media posts on Facebook and LinkedIn, then you’ll already be familiar with the words ‘Prior Art’.

Used as a generic term to describe certain communicated pre-existing inventions and ideas – usually in illustrative or written form, but not always – this guide will explore the meaning of prior art and answer some of the questions surrounding it.


What is prior art and what does the term mean in patent law?

Prior art covers everything that is known to the public before the filing date of a patent application, by means of oral or written description or any other means. That also includes public prior use of an invention. There is no restriction with regards to geographical location, language or time.

Prior art does not need to exist physically or commercially. It is enough that someone, somewhere, sometime previously has described, shown or made something that contains a use of technology that is very similar to your invention.


Why is it important when considering a patent application?

Prior art searches identify if there are any similar products or methods already in existence which could then narrow or define the scope or prospects of your patent claims. If examples are discovered which closely match your application, this could result in your invention being rejected on the grounds of not being ‘novel’ or ‘non-obvious’ enough.

A significant proportion of claim and patent invalidity cases stem from prior art triggers and it is estimated to affect approximately 12% of litigation lawsuits, which have seen a 400% increase at PTAB from 2011-2017, according to a paper published in 2019, by Stephen Yelderman, a Professor of Law at Notre Dame Law School.


What sources are considered as prior art?

This question has hundreds of answers, all being correct. Prior art can be anything, and come in any form, albeit with some exceptions – which relate more to secrecy and the amount of disclosure rather than the medium by which it is disclosed.

If the disclosure is only partial or it is deemed too brief, then the hypothetical question arises as to whether a person of ordinary skill in the art could create the invention with the limited information given. If the answer is yes, then there will be sufficient grounds to reject the patent on the novelty and non-obvious basis.

For a more detailed explanation of the terms ‘novelty’, ‘non-obvious’, and ‘person of ordinary skill in the art’ please read our article titled “An Inventor’s Guide to Understanding Patentability“.

According to the European Patent Office (EPO), anything can be prior art; a prehistoric cave painting, a centuries-old technology, even a previously described idea that could not possibly work.

Other, more common examples include photographs, illustrations, descriptions and written literature including scholarly journal articles, scientific reports, published papers, and newspapers and magazines.


Can I conduct my own prior art search?

Conducting your own prior art search is now a lot more easier and effective than it used to be, thanks to the emergence of artificial intelligence and our Quality Insights and Patent Search solutions.

There are four different types of prior art searches that can be conducted, which cover all relevant history of an applications status. They are:

  • Rejection prior art
  • Second degree prior art
  • Family prior art
  • Semantic prior art

We have published a comprehensive, step-by-step guide titled “4 Quick Ways to Perform a Patent Prior Art Search“, which details conducting your own prior art search, taking into consideration all of the various types available to ensure all bases are covered.

For the novice inventor who is unfamiliar with the patent system and process of conducting a prior art search, there are two notable search options available, Smart Search and Semantic Search.

Smart Search: A Smart Search enables users to find as many patents with the same keywords across key patent and trademark offices (PTO) worldwide. It automatically performs a keyword search based on the synonyms, related words or terms in different languages equivalent to the original query. See our quick guide on getting the most out of your Smart Search by clicking here.

Semantic Search: A Semantic Search is a type of patent search that delivers results based on keyword concepts, not exact keyword matches. In other words, Semantic Search focuses on the meaning and similarity in semantic content instead of keyword matching. This type of search excels at uncovering hidden connections and revealing similar concepts to the input criteria, it is ideal for broader, more concept-based searching. For more details on Semantic Searches read our article titled “Level Up Your Patent Search Capabilities with Semantic Search”.

For the more experienced of inventors and those familiar with the process, the Advanced Search feature in Patent Search can be manipulated in several ways to give a broad or specific inspection of the databases. These tend to be used by industry professionals, so some knowledge and search acumen is required. Our article called “Advancing Your Search Options With Advanced Search” details the benefits of this particular feature.

Another blog post that you may find interesting is “5 Must-Have Patent Search Features You Need To Succeed”.

By simply signing up for a free, no-obligation, 7-day-trial your first downloads are on us!

With the average cost of attorney fees for prior art searches starting at around US$1,500 per patent (in the US), this is a much more viable and cost effective solution.


Be wary of scams

Prior art searches have been prone to scams for many years, with companies offering ‘cheap’ solutions through internet search engines and pay-per-click advertising. Whilst these might chime to cost-saving ideas, particularly if you are on a budget, they should instead sound alarm bells.

As Benjamin Franklin once stated, “The bitterness of poor quality remains long after the sweetness of low price is forgotten.”

That said, it is no hidden secret that most law firms across the US and Europe will outsource prior art searches to practises in India and other Asian regions, so if you do want to have peace of mind by allowing someone else to carry out the work for you, then it is best to shop around.

The inventor that ducked out because of prior art

One of the most well cited cases of a prior art search invalidating a patent claim is one that involves a Donald Duck cartoon. The story is that Danish inventor Karl Krøyer came up with a solution to raise a sunken ship from the ocean floor by filling it with ping-pong balls to prevent contamination of the water supply.


After successfully carrying out the challenge he decided to patent his method. Although Krøyer was granted a patent in the UK and Germany, his application was rejected in The Netherlands. The story goes that the reason for this is because of a pre-dated Donald Duck cartoon that was discovered to depict the same method, thus canceling out his novelty claim.


The full story can be read here.

Did you find this prior art article helpful? Please leave us your comments and feedback over on our LinkedIn and Facebook pages. Also, check out our free Patent Lifecycle Management whitepaper covering everything from preparation to monetization of your patent.


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