What is the significance of the publication date for printed publications in patent law?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

The publication date of a printed publication is crucial in patent law, particularly in determining its status as prior art. According to MPEP 2152.02(b):

“Once an examiner determines that a document was published prior to the effective filing date of the claimed invention, that document becomes a ‘printed publication’ within the meaning of 35 U.S.C. 102(a)(1).”

The significance of the publication date includes:

• It establishes when the information became publicly available.
• It determines whether the publication qualifies as prior art under 35 U.S.C. 102(a)(1).
• It affects the application of grace periods and exceptions under 35 U.S.C. 102(b)(1).
• It can impact the novelty and non-obviousness analysis of a claimed invention.

Examiners and courts may require clear evidence of the exact publication date, especially for online publications or conference presentations. The burden of proving a publication date typically falls on the party asserting the reference as prior art.