An inventor loses the right to a U.S. patent if the invention is described in a printed publication anywhere in the world more than one year prior to his/her U.S. filing date [35 U.S.C 102(b)]. This usually occurs when the inventor publishes an enabling description of his/her invention over a year before the inventor files in the U.S. It can also occur when someone else (who may or may not have independently invented the same invention) publishes a description of the invention over a year before the inventor files in the U.S. This sort of delay is fatal and results in a statutory bar to patentability.
It is important to note that the act (publication of a description of the invention) can be performed by anyone, and can occur anywhere. It must, however, occur before a specific date. That date is one year before the earliest effective filing date of a provisional or nonprovisional (regular) U.S. patent application or an international (PCT) application that designates the U.S. As far as application of this rule is concerned, it matters not what the date of invention is or that the inventor(s) can claim priority of invention based on the filing date of a non-U.S. (national or regional) patent application. Only the U.S. filing date (which can be the same as PCT filing date) is considered.
The courts have interpreted the phrase "printed publication" to mean any type of document that is publicly accessible. Thus, a document is a printed publication if it is printed, handwritten, recorded on microfilm, magnetic disk or tape, posted on a Web site, etcetera. Either actual, unrestricted dissemination (even on a limited basis) or mere accessibility to the public (even if there is no evidence that someone actually received the document) is sufficient to make a prior art reference a printed publication. The date of receipt by addressees (as evidenced by routine business practices), as opposed to the mailing date, is the effective date of publication of magazines, journals, etcetera. Speeches and other oral presentations are not printed publications unless written copies of them are made available on an unrestricted basis [but see 35 U.S.C. 102(a)].