What constitutes prior art under a 102(a) rejection?

The correct answer involves understanding what constitutes prior art under Section 102(a) of the patent law. Section 102(a) defines prior art as any knowledge that has been made available to the public before the effective filing date of a patent application. This includes anything that is publicly known, used, or described, and is significant because it can affect the novelty of a claimed invention.

Specifically, public knowledge in the U.S. before the invention date is critical because it establishes that the invention was already known or disclosed to the public. If something is publicly known or used before the applicant's inventive date, it can invalidate the novelty of the claimed invention, leading to a rejection under Section 102(a).

In contrast, the publication of the patent application refers to the formal process where the patent application is made publicly available, which does not occur until after the filing date. Therefore, it cannot serve as prior art before that date.

The sale of a patented product in the U.S. can indeed be relevant, but it occurs in a context where the product must be publicly available and can contribute to a different kind of rejection based on Section 102(b) if it happens after the effective filing date.

A patent obtained in the U.S. after the