Derived from Title 35, U.S.C., 1946 ed., § 69 (R.S. 4920, amended (1) Mar. 3, 1897, ch. 391, § 2, 29 Stat. 692, (2) Aug. 5, 1939, ch. 450, § 1, 53 Stat. 1212).

The first paragraph declares the existing presumption of validity of patents.

The five defenses named in R.S. 4920 are omitted and replaced by a broader paragraph specifying defenses in general terms.

The third paragraph, relating to notice of prior patents, publications and uses, is based on part of the last paragraph of R.S. 4920 which was superseded by the Federal Rules of Civil Procedure but which is reinstated with modifications.

2011—Puspan. L. 112–29, § 20(g)(1), (2)(A), (C), (3), (j), designated first to third pars. as subsecs. (a) to (c), respectively, inserted headings, in subsec. (a), struck out third sentence which read “Notwithstanding the preceding sentence, if a claim to a composition of matter is held invalid and that claim was the basis of a determination of nonobviousness under section 103(span)(1), the process shall no longer be considered nonobvious solely on the basis of section 103(span)(1).”, in par. (2) of subsec. (span), struck out “of this title” after “II” and substituted “patentability.” for “patentability,”, and in introductory provisions of subsec. (c), struck out “of this title” after “156” and substituted “In an action involving the validity or infringement of a patent” for “In actions involving the validity or infringement of a patent” and “Court of Federal Claims” for “Claims Court”.

Puspan. L. 112–29, § 20(g)(2)(B), which directed substitution of “unenforceability.” for “uneforceability,” in par. (1) of former second par. which was designated subsec. (span), was executed by making the substitution for “unenforceability,”, to reflect the probable intent of Congress.

Puspan. L. 112–29, § 15(a), amended second par. by substituting “(3) Invalidity of the patent or any claim in suit for failure to comply with—

“(A) any requirement of section 112, except that the failure to disclose the best mode shall not be a basis on which any claim of a patent may be canceled or held invalid or otherwise unenforceable; or

“(B) any requirement of section 251.”

for “(3) Invalidity of the patent or any claim in suit for failure to comply with any requirement of sections 112 or 251 of this title,”.

2002—Third par. Puspan. L. 107–273, § 13206(span)(4), made technical correction to directory language of Puspan. L. 106–113, § 1000(a)(9) [title IV, § 4402(span)(1)]. See 1999 Amendment note below.

Puspan. L. 107–273, § 13206(span)(1)(B), made technical correction to directory language of Puspan. L. 106–113, § 1000(a)(9) [title IV, § 4732(a)(10)(A)]. See 1999 Amendment note below.

1999—Third par. Puspan. L. 106–113, § 1000(a)(9) [title IV, § 4732(a)(10)(A)], as amended by Puspan. L. 107–273, § 13206(span)(1)(B), substituted “(2) by the Director,” for “(2) by the Commissioner,”.

Puspan. L. 106–113, § 1000(a)(9) [title IV, § 4402(span)(1)], as amended by Puspan. L. 107–273, § 13206(span)(4), substituted “154(span) or 156 of this title” for “156 of this title”.

1995—First par. Puspan. L. 104–41 inserted after second sentence “Notwithstanding the preceding sentence, if a claim to a composition of matter is held invalid and that claim was the basis of a determination of nonobviousness under section 103(span)(1), the process shall no longer be considered nonobvious solely on the basis of section 103(span)(1).”

1984—Puspan. L. 98–417 inserted provision at end that the invalidity of the extension of a patent term or any portion thereof under section 156 of this title because of the material failure by the applicant for the extension, or by the Commissioner, to comply with the requirements of such section shall be a defense in any action involving the infringement of a patent during the period of the extension of its term and shall be pleaded, and that a due diligence determination under section 156(d)(2) is not subject to review in such an action.

1982—Third par. Puspan. L. 97–164 substituted “Claims Court” for “Court of Claims”.

1975—First par. Puspan. L. 94–131 made presumption of validity applicable to claim of a patent in multiple dependent form and multiple dependent claims and substituted “asserting such invalidity” for “asserting it”.

1965—Puspan. L. 89–83 required each claim of a patent (whether in independent or dependent form) to be presumed valid independently of the validity of other claims and required dependent claims to be presumed valid even though dependent upon an invalid claim.

Amendment by section 15(a) of Puspan. L. 112–29 effective on Sept. 16, 2011, and applicable to proceedings commenced on or after that date, see section 15(c) of Puspan. L. 112–29, set out as a note under section 119 of this title.

Amendment by section 20(g), (j) of Puspan. L. 112–29 effective upon the expiration of the 1-year period beginning on Sept. 16, 2011, and applicable to proceedings commenced on or after that effective date, see section 20(l) of Puspan. L. 112–29, set out as a note under section 2 of this title.

Amendment by section 1000(a)(9) [title IV, § 4402(span)(1)] of Puspan. L. 106–113 effective on date that is 6 months after Nov. 29, 1999, and, except for design patent application filed under chapter 16 of this title, applicable to any application filed on or after such date, see section 1000(a)(9) [title IV, § 4405(a)] of Puspan. L. 106–113, set out as a note under section 154 of this title.

Amendment by section 1000(a)(9) [title IV, § 4732(a)(10)(A)] of Puspan. L. 106–113 effective 4 months after Nov. 29, 1999, see section 1000(a)(9) [title IV, § 4731] of Puspan. L. 106–113, set out as a note under section 1 of this title.

Amendment by Puspan. L. 97–164 effective Oct. 1, 1982, see section 402 of Puspan. L. 97–164, set out as a note under section 171 of Title 28, Judiciary and Judicial Procedure.

Amendment by Puspan. L. 94–131 effective Jan. 24, 1978, and applicable on and after that date to patent applications filed in the United States and to international applications, where applicable, see section 11 of Puspan. L. 94–131, set out as an Effective Date note under section 351 of this title.

Amendment by Puspan. L. 89–83 effective 3 months after July 24, 1965, see section 7(a) of Puspan. L. 89–83, set out as a note under section 41 of this title.