Patent and Trademark Office
The Patent and Trademark Office examiner, after the patent application has been filed with the Patent and Trademark Office, carefully reviews the application in order to determine the invention's patentability. There is only one Patent and Trademark Office in the U.S. It is located in Arlington, Virginia, close to Washington, DC.
The Patent and Trademark Office will not tell you if your invention has already been invented by someone else unless you apply for a patent. Patent and Trademark Office can only verify that the description and claims per description by their inventors or patent attorneys, are new, unique, and not obvious to the Patent and Trademark Office. The Patent and Trademark Office examiners do not verify that an invention works or that it can ever be, or never has been, built. They try only to correctly verify that the invention is patentable and has not been patented in the U.S. before.
In making a patent application, there are some specific requirements one need to comply. An application must include a specification, including a description and claim(s); an oath or declaration identifying the applicant(s) believing to be the original inventor(s); a drawing when necessary; and the filing fee. Prior to 1870, a model of the invention was required as well. Today, a model is almost never required.
To be patentable, an invention essentially must meet the following requirements set by Patent and Trademark Office which are: (1) useful, (2) novel, and (3) non-obvious. The novelty requirement of Patent and Trademark Office is often consider the entry test for patentability. The probably more demanding, non-obviousness requirement is harder to objectively define. The typical way that an examiner in Patent and Trademark Office shows obviousness is to cite a number of prior art references that, when combined as suggested by possibly another prior art reference, contain all of the elements of the applicant's invention.
Inventors can make a search of patents already granted, text books, journals and other publications to be sure that someone else has not already invented their idea. They may hire someone to do it for them or may do this themselves at the Public Search Room of the U.S. Patent and Trademark Office in Arlington, Virginia, on the PTO web page on the Internet, or at one of the Patent and Trademark Depository Libraries across the country. The patent cost can be very high for some people which the U.S. Patent and Trademark Office charges a minimum of about $4,000 over the life of the patent.