MPEP 2138.01
Interference Practice

This is the Ninth Edition of the MPEP, Revision 08.2017, Last Revised in Januay 2018

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2138.01    Interference Practice [R-08.2017]

[Editor Note: This MPEP section has limited applicability to applications subject to examination under the first inventor to file (FITF) provisions of the AIA as set forth in 35 U.S.C. 100 (note). See MPEP § 2159 et seq. to determine whether an application is subject to examination under the FITF provisions, MPEP § 2159.03 for the conditions under which this section applies to an AIA application, and MPEP § 2150 et seq. for examination of applications subject to those provisions.]

I.    PRE-AIA 35 U.S.C. 102(g) IS THE BASIS OF INTERFERENCE PRACTICE

Subsection (g) of pre-AIA 35 U.S.C. 102 is the basis of interference practice for determining priority of invention between two parties. See Bigham v. Godtfredsen, 857 F.2d 1415, 1416, 8 USPQ2d 1266, 1267 (Fed. Cir. 1988), 35 U.S.C. 135, 37 CFR Part 41, Subparts D and E and MPEP Chapter 2300. An interference is an inter partes proceeding directed at determining the first to invent as among the parties to the proceeding, involving two or more pending applications naming different inventors or one or more pending applications and one or more unexpired patents naming different inventors. The United States is unusual in having a first to invent rather than a first to file system in certain applications. Paulik v. Rizkalla, 760 F.2d 1270, 1272, 226 USPQ 224, 225 (Fed. Cir. 1985) (reviews the legislative history of the subsection in a concurring opinion by Judge Rich). The first of many to reduce an invention to practice around the same time will be the sole party to obtain a patent in some instances, Radio Corp. of America v. Radio Eng’g Labs., Inc., 293 U.S. 1, 2, 21 USPQ 353, 353-4 (1934), unless another was the first to conceive and couple a later-in-time reduction to practice with diligence from a time just prior to when the second conceiver entered the field to the first conceiver’s reduction to practice. Hull v. Davenport, 90 F.2d 103, 105, 33 USPQ 506, 508 (CCPA 1937). See the priority time charts below illustrating this point. Upon conclusion of an interference, subject matter claimed by the losing party that was the basis of the interference is rejected under pre-AIA 35 U.S.C. 102(g), unless the acts showing prior invention were not in this country.

It is noted that 35 U.S.C. 101 requires that whoever invents or discovers the claimed invention is the party that must be named as the inventor(s) before a parent may be granted. Where it can be shown that an applicant has "derived" an invention from another, a rejection under pre-AIA 35 U.S.C. 102(f) is proper if applicable. Ex parte Kusko, 215 USPQ 972, 974 (Bd. App. 1981) ("most, if not all, determinations under [pre-AIA] Section 102(f) involve the question of whether one party derived an invention from another"); Price v. Symsek, 988 F.2d 1187, 1190, 26 USPQ2d 1031, 1033 (Fed. Cir. 1993) (Although derivation and priority of invention both focus on inventorship, derivation addresses originality, i.e., who invented the subject matter, whereas priority focuses on which party invented the subject matter first.).

II.    PRIORITY TIME CHARTS

The following priority time charts illustrate the award of invention priority in several situations. The time charts apply to interference proceedings and are also applicable to declarations or affidavits filed under 37 CFR 1.131 to antedate references which are available as prior art under pre-AIA 35 U.S.C. 102(a) or 102(e). Note, however, in the context of 37 CFR 1.131, an applicant does not have to show that the invention was not abandoned, suppressed, or concealed from the time of an actual reduction to practice to a constructive reduction to practice because the length of time taken to file a patent application after an actual reduction to practice is generally of no consequence except in an interference proceeding. Paulik v. Rizkalla, 760 F.2d 1270, 226 USPQ 224 (Fed. Cir. 1985). See the discussion of abandonment, suppression, and concealment in MPEP § 2138.03.

For purposes of analysis under 37 CFR 1.131, the conception and reduction to practice of the reference to be antedated are both considered to be on the effective filing date of domestic patent or foreign patent or the date of printed publication.

In the charts, C = conception, R = reduction to practice (either actual or constructive), Ra = actual reduction to practice, Rc = constructive reduction to practice, and TD = commencement of diligence.

Example 1
Priority Time Chart Example 1

A is awarded priority in an interference, or antedates B as a reference in the context of a declaration or affidavit filed under 37 CFR 1.131, because A conceived the invention before B and constructively reduced the invention to practice before B reduced the invention to practice. The same result would be reached if the conception date was the same for both inventors A and B.

Example 2
Priority Time Chart Example 2

A is awarded priority in an interference, or antedates B as a reference in the context of a declaration or affidavit filed under 37 CFR 1.131, if A can show reasonable diligence from TD (a point just prior to B’s conception) until Rc because A conceived the invention before B, and diligently constructively reduced the invention to practice even though this was after B reduced the invention to practice.

Example 3
Priority Time Chart Example 3

A is awarded priority in an interference in the absence of abandonment, suppression, or concealment from Ra to Rc, because A conceived the invention before B, actually reduced the invention to practice before B reduced the invention to practice, and did not abandon, suppress, or conceal the invention after actually reducing the invention to practice and before constructively reducing the invention to practice.

A antedates B as a reference in the context of a declaration or affidavit filed under 37 CFR 1.131 because A conceived the invention before B and actually reduced the invention to practice before B reduced the invention to practice.

Example 4
Priority Time Chart Example 4

A is awarded priority in an interference if A can show reasonable diligence from TD (a point just prior to B’s conception) until Ra in the absence of abandonment, suppression, or concealment from Ra to Rc, because A conceived the invention before B, diligently actually reduced the invention to practice (after B reduced the invention to practice), and did not abandon, suppress, or conceal the invention after actually reducing the invention to practice and before constructively reducing the invention to practice.

A antedates B as a reference in the context of a declaration or affidavit filed under 37 CFR 1.131 because A conceived the invention before B, and diligently actually reduced the invention to practice, even though this was after B reduced the invention to practice.

III.    37 CFR 1.131 DOES NOT APPLY IN INTERFERENCE PROCEEDINGS

Interference practice operates to the exclusion of ex parte practice under 37 CFR 1.131 which permits an applicant to show an actual date of invention prior to the effective date of a reference or activity applied under pre-AIA 35 U.S.C. 102 or 103, as long as the reference is not a statutory bar under pre-AIA 35 U.S.C. 102(b) or a U.S. patent application publication claiming the same patentable invention. Ex parte Standish, 10 USPQ2d 1454, 1457 (Bd. Pat. App. & Inter. 1988) (An application claim to the "same patentable invention" claimed in a domestic patent requires interference rather than an affidavit under 37 CFR 1.131 to antedate the patent. The term "same patentable invention" encompasses a claim that is either anticipated by or obvious in view of the subject matter recited in the patent claim.). Subject matter which is prior art under pre-AIA 35 U.S.C. 102(g) and is subject to an interference is not open to further inquiry under 37 CFR 1.131 during the interference proceeding.

IV.    LOST COUNTS IN AN INTERFERENCE ARE NOT, PER SE, STATUTORY PRIOR ART

Loss of an interference count alone does not make its subject matter statutory prior art to losing party; however, lost count subject matter that is available as prior art under 35 U.S.C. 102 may be used alone or in combination with other references under 35 U.S.C. 103. But see In re Deckler, 977 F.2d 1449, 24 USPQ2d 1448 (Fed. Cir. 1992) (Under the principles of res judicata and collateral estoppel, Deckler was not entitled to claims that were patentably indistinguishable from the claim lost in interference even though the subject matter of the lost count was not available for use in an obviousness rejection under 35 U.S.C. 103.).