- A person shall be entitled to a patent unless— ...(b) the invention was patented or described in a printed publication in this or a foreign country or in public use or on sale in this country, more than one year prior to the date of the application for patent in the United States, ...
This is the one year bar. Sometimes, because of the “on sale” provision, it is referred to as the On-Sale Bar. There are two parts, first, the invention must be “ready for patenting”, i.e., the invention is at the stage where a patent application could be filed. Second, it must either be (a) described in a printed publication, (b) put in public use, or (c) put on sale. These are all gray areas and if you have to look closely at them, you might already be in trouble. The safest course is to keep the invention confidential until you are ready to go to market. At that stage, file a patent application, get the “patent pending” status, and go to market. Not vice versa.
How does anyone know? Can you just keep your barring public use or barring sale secret and still get a patent? There are two aspects to this, legal and moral. The entrepreneur needs to make the moral decision for themselves.
The legal aspect is straightforward. When you file a patent application, you sign a declaration, under Federal law (thus, willful violation of which could be a Federal crime), that you know and understand your duty to disclose all information material to patentability to the Patent Office. When you don’t do so, it is called inequitable conduct. If the Patent Office finds out, it can bar your patent. If a patent issues and a competitor finds out, it can invalidate your patent and open you up to liability for bad faith patent enforcement. Every year patents are invalidated based on inequitable conduct for failure to disclose. It is not a situation you want to be in, especially since there is an easy way to avoid the problem -- apply for patent first, and then market the product. Otherwise, you could end up dedicating your invention to the public.
Note, some countries/regions don't allow a one year grace period at all. An IP entrepreneur that considers international protection will want to check the countries he or she is interested in before doing an act that starts the clock ticking. There may be less time than the one year allowed in the US, or no time at all.