If you have a great idea, you’ll want to protect it. But what exactly are the criteria for patent protection?
Patents protect new inventions. They are intended to reward inventors by providing a monopoly over commercial exploitation of the invention for a limited period. In return, the inventor is expected to fully disclose the invention so that it is available for all to use after the patent expires.
Certain types of subject-matter are specifically excluded from the possibility of patent protection. Examples include computer programs, business methods, and methods of surgery. Excluded subject matter is more fully explained in a separate article.
Assuming your invention does not fall into one of the excluded categories, a patent can be granted for an invention which is novel, involves an inventive step, and is industrially applicable.
This is the most basic criterion. No patent can be granted to an invention which is not new. In the UK, and in most other countries, a fairly strict line is taken in assessing novelty. Any disclosure, anywhere in the world, whether it is written down or not, is potentially prejudicial to a patent application if the disclosure is before the priority date of the application.
Because prior disclosure can destroy a patent application, it is crucial to keep your invention secret until an application has been filed. However, this is not quite the whole story. There are a few cases where it might seem that an invention has been disclosed, but in fact a patent can be granted.
Disclosure must be enabling
To prejudice a patent application, it is not enough that the invention has simply been shown. It must have been disclosed in a way which would enable a skilled person to put it into practice. For example, a motor company which develops a new engine and tests it on public roads would not necessarily destroy its chances of patent protection, since a person who observes the car drive past would not be able to discern the workings of the engine.
Disclosure must be to the public
An invention may still be new if it has been disclosed only to a particular group of people. However, if there was some expectation that those people would, or even could, further disseminate that information then the disclosure is considered to be to the public. Furthermore, any document is regarded as having been disclosed to the public if members of the public could have read the document (for example, because it is in a public library), even if, in reality, nobody did read it.
Disclosure must not be in breach of confidence
If information is disclosed to a person, or to a group of people, in conditions of confidentiality, and that information is subsequently disclosed to the public in breach of confidence, a patent may still be validly applied for, provided that the application is filed within six months of the disclosure.
Although conditions of confidence can arise without any written document, obtaining a signed confidentiality agreement before disclosing your invention to anybody is always wise.
There is also an exception for disclosures made at officially recognised exhibitions, although in practice very few exhibitions are officially recognised.