A rule 131 affidavit/declaration allows an inventor of an application or the owner of a patent under reexamination to swear behind a reference which is being applied under 35 USC 102(a) and/or 35 USC 102(e) unless the reference is (1) a statutory bar or (2) is a US patent or a published US application which claims the “same patentable invention” as the rejected claim. The term “statutory bar” refers to a reference which are prior art under 35 USC 102(b).
A reference claims “the same patentable invention” if the subject matter of a claim of one party would, if prior art, have anticipated or rendered obvious the subject matter of a claim of the opposing party and vice versa. If the two-way test is satisfied (i.e., the rejected claim recites the “same patentable invention” as the claims in the reference US patent or published US application), an applicant can either (1) file a Rule 130 affidavit or declaration to avoid the reference in an obviousness rejection (if commonly owned) or (2) file a request under 37 CRR 41.202 for declaration of an interference.
Formalities: When to File/Signatures
A 131 affidavit must be presented prior to final rejection or before appeal in an application not having a final rejection. Under certain situations a Rule 131 affidavit can be submitted after appeal.
All of the inventors of the subject matter of the rejected claim must sign the 131 affidavit with some exceptions such as where some or all of the inventors cannot sign.
What to include in your 1.131 affidavit
You must present facts/evidence to establish reduction to practice (either actual or constructive) prior to the effective date of the reference being applied against you or conception of your invention prior to the effective date of your reference coupled with due diligence from prior to this date to a subsequent reduction to practice or to the filing of your patent application. The term “conception” is the formation in the mind of the inventor of a definite and permanent idea of the complete and operative invention as it is to be thereafter applied in practice. The test is whether the concept of the invention is clear enough for one skilled in the art to actually reduce it to practice without undue experimentation. The term “actual reduction to practice” occurs when the claimed invention is actually made (e.g., an apparatus is assembled) or performed (e.g., for a method) and seen to be suitable for its intended purpose. The term “constructive reduction to practice” means a filing of a US patent application meeting the written description requirement. The term “due diligence” is the reasonable effort to reduce your invention to practice.
It is important to remember when completing a 131 affidavit that when you are providing your examiner evidence of a date of invention that the location of these acts is important; they must have been preformed in the U.S. or in a NAFTA country (Mexico; Canada) to prove a date of invention on or after 12/8/93 or in a WTO country to provide a date of invention on or after 1/1/96. If you do not specifically state in your affidavit where your acts were performed, you are likely to have your 1.131 rejected.
For more information on 1.131 affidavits see MPEP sections 715-715.10 which covers swearing back of a reference and 2138-2138.06 which covers conception, diligence, and reduction to practice