35 U.S.C. · Part II · Chapter 10, Patentability of inventions

35 U.S.C. 100: Definitions

In plain English

Section 100 defines words the rest of Title 35 relies on. Some are housekeeping: an “invention” includes a discovery, the “United States” includes its territories and possessions, and a “patentee” includes successors in title. The definitions that do real work were added by the America Invents Act: “inventor” and “joint inventor” in subsections (f) and (g), “joint research agreement” in (h), “effective filing date” in (i) and “claimed invention” in (j).

The effective filing date is set claim by claim. A claim takes the actual filing date of its application, unless the application is entitled, for that claim, to foreign priority (sections 119, 365(a) or (b), 386(a) or (b)) or to the benefit of an earlier US filing (sections 120, 121, 365(c), 386(c)). Then the claim takes the filing date of the earliest application that supports it. Two claims in the same patent can have different effective filing dates, and prior art is measured against each one separately.

Subsection (b) is easy to miss. A “process” includes a new use of a known process, machine, manufacture, composition of matter or material. That is why method-of-use claims, such as a new treatment using a known compound, fit within section 101 in the United States.

Annotation by Raj Sutariya, Co-founder, PatentAssist.ai. General information, not legal advice; the statute below governs.

AIA and pre-AIA

The effective filing date also decides which version of the novelty and obviousness rules applies. An application is examined under the AIA first-inventor-to-file rules if it contains, or ever contained, a claim with an effective filing date on or after March 16, 2013, or a specific reference to an application that did. Applications whose claims all date from before then stay under pre-AIA sections 102 and 103.

Text of 35 U.S.C. 100

Current text, quoted from the official United States Code.

When used in this title unless the context otherwise indicates—
(a) The term “invention” means invention or discovery.
(b) The term “process” means process, art or method, and includes a new use of a known process, machine, manufacture, composition of matter, or material.
(c) The terms “United States” and “this country” mean the United States of America, its territories and possessions.
(d) The word “patentee” includes not only the patentee to whom the patent was issued but also the successors in title to the patentee.
(e) The term “third-party requester” means a person requesting ex parte reexamination under section 302 who is not the patent owner.
(f) The term “inventor” means the individual or, if a joint invention, the individuals collectively who invented or discovered the subject matter of the invention.
(g) The terms “joint inventor” and “coinventor” mean any 1 of the individuals who invented or discovered the subject matter of a joint invention.
(h) The term “joint research agreement” means a written contract, grant, or cooperative agreement entered into by 2 or more persons or entities for the performance of experimental, developmental, or research work in the field of the claimed invention.
(i) (1) The term “effective filing date” for a claimed invention in a patent or application for patent means—
(A) if subparagraph (B) does not apply, the actual filing date of the patent or the application for the patent containing a claim to the invention; or
(B) the filing date of the earliest application for which the patent or application is entitled, as to such invention, to a right of priority under section 119, 365(a), 365(b), 386(a), or 386(b) or to the benefit of an earlier filing date under section 120, 121, 365(c), or 386(c).
(2) The effective filing date for a claimed invention in an application for reissue or reissued patent shall be determined by deeming the claim to the invention to have been contained in the patent for which reissue was sought.
(j) The term “claimed invention” means the subject matter defined by a claim in a patent or an application for a patent.

Practical notes

A continuation-in-part is where the claim-by-claim rule bites. Claims fully supported by the parent keep the parent's date; claims that need the new matter get the CIP's own filing date and face everything published in between. Map each claim to its support before relying on an earlier date, because the support has to meet the written description requirement of section 112(a).

Foreign priority counts for the effective filing date but not for patent term. Section 154(a)(3) measures the 20-year term from the US or PCT filing date, so claiming priority to a foreign application filed 12 months earlier gains prior-art protection without shortening the term.

The joint research agreement definition matters only if you plan to rely on the exception in section 102(c). The agreement must be written and in effect on or before the effective filing date, and the application must name the parties.

Related rules and guidance

37 CFR: § 1.9, § 1.109, § 1.110, § 1.55, § 1.78
MPEP: 2109, 2152.01, 2156, 2159