In order for an invention to be patentable it must be new as defined in the patent law, which provides that an invention cannot be patented if:

“(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention” or

“(2) the claimed invention was described in a patent issued [by the U.S.] or in an application for patent published or deemed published [by the U.S.], in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.”

There are certain limited patent law exceptions to patent prohibitions (1) and (2) above. Notably, an exception may apply to a “disclosure made 1 year or less before the effective filing date of the claimed invention,” but only if “the disclosure was made by the inventor or joint inventor or by another who obtained the subject matter disclosed… from the inventor or a joint inventor.”

In patent prohibition (1), the term “otherwise available to the public” refers to other types of disclosures of the claimed invention such as, for example, an oral presentation at a scientific meeting, a demonstration at a trade show, a lecture or speech, a statement made on a radio talk show, a YouTube™ video, or a website or other on-line material.

Effective filing date of the claimed invention: This term appears in patent prohibitions (1) and (2). For a U.S. nonprovisional patent application that is the first application containing the claimed subject matter, the term “effective filing date of the claimed invention” means the actual filing date of the U.S. nonprovisional patent application. For a U.S. nonprovisional application that claims the benefit of a corresponding prior-filed U.S. provisional application, “effective filing date of the claimed invention” can be the filing date of the prior-filed provisional application provided the provisional application sufficiently describes the claimed invention. Similarly, for a U.S. nonprovisional application that is a continuation or division of a prior-filed U.S. nonprovisional application, “effective filing date of the claimed invention” can be the filing date of the prior filed nonprovisional application that sufficiently describes the claimed invention. Finally, “effective filing date of the claimed invention” may be the filing date of a prior-filed foreign patent application to which foreign priority is claimed provided the foreign patent application sufficiently describes the claimed invention.

Even if the subject matter sought to be patented is not exactly shown by the prior art, and involves one or more differences over the most nearly similar thing already known, a patent may still be refused if the differences would be obvious. The subject matter sought to be patented must be sufficiently different from what has been used or described before that it may be said to be non-obvious to a person having ordinary skill in the area of technology related to the invention. For example, the substitution of one color for another, or changes in size, are ordinarily not patentable.