Patentability requirements can be complex and abstract, and are defined by US Federal statutes and US Federal regulations. This discussion can only serve as a summary of basic issues.
What is prior art?
Prior art includes any information, such as patents, patent applications, public use, printed publications, on-sale activities, etc. that were publicly available prior to the filing date of your earliest patent application. Information you (the inventor) disclosed not more than a year before the filing date of your patent application does not normally constitute prior art.
From where may prior art information be cited for rejecting patent claims?
Prior art includes any information related to use, publication, knowledge, or on-sale activities of your invention prior to the filing date of your earliest patent application, regardless of which country the prior use or on-sale activities occurred.
What are the basic legal requirements in the US for a utility patent to be granted on an invention?
For an invention to receive a utility patent under U.S. patent law, it must meet four basic requirements:
1. The invention itself (as opposed to its patent claims) must be classified as either a process, a machine, a composition of matter, or a manufacture.
2. The invention must possess practical utility as opposed to ornamental value.
3. The invention’s patent claims must be novel.
4. The invention’s patent claims must be unobvious (or this is sometimes referred to as nonobvious).
What is novelty?
For an invention’s patent claims to be novel, all the elements recited in the patent application’s claims must not be disclosed in any single prior art reference, (with a possible exception if the inventor himself made the information public not more than one year before the inventor filed a patent application).
If the claims in a patent application are disclosed in any single prior art reference, the claims will normally be rejected by the US Patent Office for lack of novelty.
What is unobviousness?
The legal concepts of unobviousness are rather complex, and this requirement is typically the most difficult requirement to meet for many inventors. To be unobvious, an invention’s patent claims must represent some type of qualitative advance over earlier technology to justify a patent. For example, the invention must provide one or more new and unexpected results, or all the elements of an invention’s patent claim must not already be disclosed in any combination of “prior art” references previously disclosed (see “prior art” above).
Another explanation of unobviousness might state that for an invention to be patentable, an invention must demonstrate a required level of innovation and ingenuity from the objective viewpoint of a person having “ordinary skill in the art” of the invention.
Note: Both novelty and unobviousness are complex legal subjects and the information presented here does not represent a comprehensive discussion of these topics.
Do I need to build and test my invention before filing a patent application?
On March 16, 2013, the new first-to-file US patent law took effect. For patent applications filed on that date or later, an inventor may no longer “swear behind” an earlier “prior art” reference used to reject his patent claims. An inventor, whose patent application was filed before 03/16/2013, could swear behind a prior art reference IF they built and tested their invention prior to the reference’s effective date, or (possibly) if the inventor only conceived and built the invention prior to the reference’s effective date. So before 03/16/2013 it was more essential for an inventor to build and test his invention before filing a patent application.
However, even after 03/16/2013, it is certainly good practice to build and test your invention as soon as possible after you conceive it. During your conception, building, and testing phases, its also good practice to carefully document, sign, and date your invention activities, and include witness signatures if possible.