Prior art is publicly available information that may pertain to a patent application, potentially invalidating the patent. When people file for patents to protect inventions, they must be able to show that the invention is novel, presenting an entirely new idea. Prior art can disprove this claim, showing that similar concepts and ideas were known to members of the general public before the patent was filed. If this occurs, a patent will not be granted.
When people get ready to file a patent application, one of the things they may do is search for prior art. They are also required to disclose any known public information about the patent they are aware of, such as patents for components of the invention, demonstrations that may have been held for the public, and disclosures about the nature of the invention. All of this information is considered by the patent examiner, who will also conduct an investigation to look for prior art.
The patent examiner is looking for a demonstration of originality, showing that someone has a concept that is new. It may be a new way of doing something or a completely original idea. For example, the electric washing machine is a distinctly different approach to laundering than a washboard, while an aircraft is a completely original idea. If the patent examiner determines that the novelty standard is met, the patent can be granted.
Prior art can be a contentious and complicated topic. During the development of items people wish to patent, key information sometimes has to be released to work on fabricating parts and testing the product. This could be considered prior art, unless it is offered under the terms of a nondisclosure agreement, binding people exposed to that information to secrecy on the grounds that a trade secret is involved.
Likewise, people may contest claims that prior art disproves the originality of a patent. People applying for patents may attempt to demonstrate that although similar concepts are known to the public, the item being patented truly is unique and distinct. Other concerns can include situations where the person who files first is not actually the inventor. Some nations have a “first to file” policy, allowing people to claim patents for inventions that aren't theirs if they can get to the patent office first. This provides an incentive for filing information about an invention as soon as possible, facilitating public access to new inventions that may improve quality of life.