When you apply for a Patent application, your invention is compared to Prior Art. If the patent office examiner assigned to your patent application considers your invention too similar to prior art, the patent examiner may decide to reject your patent application. So what is prior art? Prior art is anything in the public that is already known. This could be existing patents that were filed before you, but it does not have to be. Prior art could be patent applications that were rejected or pending, or it could even be a publication, journal, or website.

Let’s put it simply. Prior art is anything in the public that is similar to your invention. It doesn’t have to be a patent. It could be a website where someone is selling something similar to yours. It could be an article, publication, or even a patent application that was applied for but rejected. The point is, if someone has thought of something similar to your invention prior to you, and that evidence can be found in the public, it could be prior art used by a patent examiner who is deciding if your invention is patentable. Let’s list some more examples:

1) Patents, worldwide, active or expired

If something is already patented, it is easily found by patent examiners as they have access to worldwide patent databases. Patents worldwide are prior art, not just those in the US. So if somebody already invented your invention in Europe, for example, the examiner can use that patent as prior art and say your invention has already been thought of and is not patentable in the US. Keep in mind that this includes even expired patents. A patent that has expired means anyone can make that invention. However, that expired patent is still prior art because remember, anything in the public can be prior art.

2) Not approved patents, worldwide

When an inventor files a non-provisional patent application, it is usually published into the patent database for the public to see, regardless of whether the patent application is approved, rejected, or will be approved or rejected. It is simply part of the patent application process. So even if the patent application is eventually rejected by the patent office, this publication stays in the public patent database and therefore can be used as prior art. It makes sense though, because to get a patent, you need to be the first one to invent it. If someone already invented it in the past, that means you are not the first one. It doesn’t matter that the other someone never got their patent. The fact is, they thought of it prior to you, so their patent application can be used as prior art to say that you didn’t invent the invention first, regardless of if they get the patent or not themselves.

3) Journals, publications, articles

Anything in the public is prior art. So, this includes any documents published in print or on the web. If someone wrote an article about an invention similar to yours, the patent office could use that article as prior art to say that you were not the first to invent such an invention.

4) Websites

Someone selling a similar product on their website could be used as prior art by the patent office to say you are not the first to invent the invention. Even if that person selling the product doesn’t have a patent, his website alone could be prior art used by the patent office. The point is that it doesn’t matter if someone has a patent themselves. If someone has disclosed an invention similar to yours, regardless of if they have a patent, that disclosure can be used as prior art by the patent office to say you do not deserve a patent because your invention has already been thought of by someone else. We’ve seen patent examiners reject a patent application using an eBay or Amazon website. We’ve even seen clever patent examiners use Wayback Machine, a website that keeps screenshots of what websites look like in the past to say that an inventor’s invention was already disclosed by some website at some time in history, even though that website no longer shows the same content. Anything in the public can be used!

With so many different types of prior art, it is common to have a patent search performed before filing a patent application. Although not an exact science or guarantee that an invention is patentable, a patent search can show you some likely prior art a patent examiner may use, before you file a patent application, and even give you an opportunity to work around the prior art to maximize your chances of patent approval.