Novelty — 35 USC §102 and the AIA on-sale / public-use bars
**35 USC §102 (AIA, effective 2013-03-16):** A person shall be entitled to a patent unless the claimed invention was:
**§102(a)(1) prior art:** • Patented, or • 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.
**§102(a)(2) prior art:** described in a patent/published application that names another inventor and has an effective filing date before the claimed invention's effective filing date.
**§102(b)(1) — 1-year grace period exceptions** to 102(a)(1): • Disclosure by the inventor (or someone who obtained from the inventor) within 1 year before filing. • Disclosure by another of subject matter that had previously been publicly disclosed by the inventor.
**§102(b)(2) — exceptions to 102(a)(2):** • Subject matter obtained from the inventor. • Subject matter previously publicly disclosed by the inventor. • Commonly owned or joint-research-agreement disclosures.
**Anticipation (MPEP §2131):** a single reference must disclose every element of the claim, arranged as in the claim, either expressly or inherently. If inherent, the missing property must necessarily be present (not merely possible).
**Pre-AIA §102 (applications filed before 2013-03-16):** first-to-invent system with §102(a), (b) on-sale/public-use bar with different 1-year window referenced to US activity.
**On-sale bar (Helsinn, 2019):** an offer for sale — even confidential — can trigger the on-sale bar if the invention is ready for patenting.