Where a patentee’s own products or publications become prior art against the patent it has filed to protect the invention used in the product or described in the publication. It can readily happen where, for example, a product is launched after a priority patent application has been filed, but that application turns out not to provide a sound basis for priority. United States patent law contains an exception that reduces the risk of self-collision, §102(b)(2), which excludes as prior art patents filed by the same inventor or inventors, joint inventors who obtained the information from the inventor (i.e., filings with an undisclosed inventor) and inventions under joint ownership, provided that this situation pertained as of the effective filing date of the patent, and it also provides for a 1-year grace period. See Priority Date, Grace Period.