MPEP 2133.03(a)
"Public Use"

Ninth Edition of the MPEP, Revision 10.2019, Last Revised in June 2020

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2133.03(a)    "Public Use" [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, and MPEP § 2150 et seq. for examination of applications subject to those provisions. See MPEP § 2152.02(c) through (e) for a detailed discussion of the public use and on sale provisions of AIA 35 U.S.C. 102.]


The public use bar under pre-AIA 35 U.S.C. 102(b) arises where the invention is in public use before the critical date and is ready for patenting. Invitrogen Corp. v. Biocrest Manufacturing L.P., 424 F.3d 1374, 76 USPQ2d 1741 (Fed. Cir. 2005). As explained by the court,

The proper test for the public use prong of the [pre-AIA] § 102(b) statutory bar is whether the purported use: (1) was accessible to the public; or (2) was commercially exploited. Commercial exploitation is a clear indication of public use, but it likely requires more than, for example, a secret offer for sale. Thus, the test for the public use prong includes the consideration of evidence relevant to experimentation, as well as, inter alia, the nature of the activity that occurred in public; public access to the use; confidentiality obligations imposed on members of the public who observed the use; and commercial exploitation…. That evidence is relevant to discern whether the use was a public use that could raise a bar to patentability, but it is distinct from evidence relevant to the ready for patenting component of Pfaff ’s two-part test, another necessary requirement of a public use bar.

Id. at 1380, 76 USPQ2d at 1744 (citations omitted). See MPEP § 2133.03(c) for a discussion of the "ready for patenting" prong of the public use and on sale statutory bars.

"[T]o constitute the public use of an invention it is not necessary that more than one of the patent articles should be publicly used. The use of a great number may tend to strengthen the proof, but one well defined case of such use is just as effectual to annul the patent as many." Likewise, it is not necessary that more than one person use the invention. Egbert v. Lippmann, 104 U.S. 333, 336 (1881).


Mere knowledge of the invention by the public does not warrant rejection under pre-AIA 35 U.S.C. 102(b). Pre-AIA 35 U.S.C. 102(b) bars public use or sale, not public knowledge. TP Labs., Inc. v. Professional Positioners, Inc., 724 F.2d 965, 970, 220 USPQ 577, 581 (Fed. Cir. 1984).

Note, however, that public knowledge may provide grounds for rejection under pre-AIA 35 U.S.C. 102(a). See MPEP § 2132.

A.    Commercial Versus Noncommercial Use and the Impact of Secrecy

There are limited circumstances in which a secret or confidential use of an invention may give rise to the public use bar. "[S]ecrecy of use alone is not sufficient to show that existing knowledge has not been withdrawn from public use; commercial exploitation is also forbidden." Invitrogen, 424 F.3d at 1382, 76 USPQ2d at 1745-46 (The fact that patentee secretly used the claimed invention internally before the critical date to develop future products that were never sold was by itself insufficient to create a public use bar to patentability.).

1.    "Public Use" and "Non-secret Use" Are Not Necessarily Synonymous

"Public" is not necessarily synonymous with "non- secret." The fact "that non-secret uses of the device were made [by the inventor or someone connected with the inventor] prior to the critical date is not itself dispositive of the issue of whether activity barring a patent under pre-AIA 35 U.S.C. 102(b) occurred. The fact that the device was not hidden from view may make the use not secret, but nonsecret use is not ipso facto ‘public use’ activity. Nor, it must be added, is all secret use ipso facto not ‘public use’ within the meaning of the statute," if the inventor is making commercial use of the invention under circumstances which preserve its secrecy. TP Labs., Inc. v. Professional Positioners, Inc., 724 F.2d 965, 972, 220 USPQ 577, 583 (Fed. Cir. 1983) (citations omitted).

2.    Even If the Invention Is Hidden, Inventor Who Puts Machine or Article Embodying the Invention in Public View Is Barred from Obtaining a Patent as the Invention Is in Public Use

When the inventor or someone connected to the inventor puts the invention on display or sells it, there is a "public use" within the meaning of pre-AIA 35 U.S.C. 102(b) even though by its very nature an invention is completely hidden from view as part of a larger machine or article, if the invention is otherwise used in its natural and intended way and the larger machine or article is accessible to the public. In re Blaisdell, 242 F.2d 779, 783, 113 USPQ 289, 292 (CCPA 1957); Hall v. Macneale, 107 U.S. 90, 96-97 (1882); Ex parte Kuklo, 25 USPQ2d 1387, 1390 (Bd. Pat. App. & Inter. 1992) (Display of equipment including the structural features of the claimed invention to visitors of laboratory is public use even though public did not see inner workings of device. The person to whom the invention is publicly disclosed need not understand the significance and technical complexities of the invention.).

3.    There Is No Public Use If Inventor Restricted Use to Locations Where There Was a Reasonable Expectation of Privacy and the Use Was for His or Her Own Enjoyment

An inventor’s private use of the invention, for his or her own enjoyment is not a public use. Moleculon Research Corp. v. CBS, Inc., 793 F.2d 1261, 1265, 229 USPQ 805, 809 (Fed. Cir. 1986) (Inventor showed inventive puzzle to close friends while in his dorm room and later the president of the company at which he was working saw the puzzle on the inventor’s desk and they discussed it. Court held that the inventor retained control and thus these actions did not result in a "public use.").

4.    The Presence or Absence of a Confidentiality Agreement is Not Dispositive of the Public Use Issue

"The presence or absence of a confidentiality agreement is not dispositive of the public use issue, but ‘is one factor to be considered in assessing all the evidence.’" Bernhardt, L.L.C. v. Collezione Europa USA, Inc., 386 F.3d 1371, 1380-81, 72 USPQ2d 1901, 1909 (Fed. Cir. 2004) (quoting Moleculon Research Corp. v. CBS Inc., 793 F.2d 1261, 1266, 229 USPQ 805, 808 (Fed. Cir. 1986)). The court stressed that it is necessary to analyze the evidence of public use in the context of policies that underlie the public use and on sale bar that include "‘discouraging removal of inventions from the public domain that the public justifiably believes are freely available, prohibiting an extension of the period for exploiting an invention, and favoring prompt and widespread disclosure of inventions.’" Bernhardt, 386 F.3d at 1381, 72 USPQ2d at 1909. See also Invitrogen, 424 F.3d at 1379, 76 USPQ2d at 1744; MPEP § 2133.03, subsection I. Evidence that the court emphasized included the "‘nature of the activity that occurred in public; the public access to and knowledge of the public use; [and] whether there were any confidentiality obligations imposed on persons who observed the use.’" Bernhardt, 386 F.3d at 1381, 72 USPQ2d at 1909. For example, the court in Bernhardt noted that an exhibition display at issue in the case "was not open to the public, that the identification of attendees was checked against a list of authorized names by building security and later at a reception desk near the showroom, that attendees were escorted through the showroom, and that the attendees were not permitted to make written notes or take photographs inside the showroom." Id. The court remanded the issue of whether the exhibition display was a public use for further proceedings since the district court "focused on the absence of any confidentiality agreements and did not discuss or analyze how the totality of the circumstances surrounding" the exhibition "comports with the policies underlying the public use bar." Id.

B.    Use by Third Parties Deriving the Invention from Applicant

   An Invention Is in Public Use If the Inventor Allows Another To Use the Invention Without Restriction or Obligation of Secrecy

"Public use" of a claimed invention under pre-AIA 35 U.S.C. 102(b) occurs when the inventor allows another person to use the invention without limitation, restriction or obligation of secrecy to the inventor." In re Smith, 714 F.2d 1127, 1134, 218 USPQ 976, 983 (Fed. Cir. 1983). The presence or absence of a confidentiality agreement is not itself determinative of the public use issue, but is one factor to be considered along with the time, place, and circumstances of the use which show the amount of control the inventor retained over the invention. Moleculon Research Corp. v. CBS, Inc., 793 F.2d 1261, 1265, 229 USPQ 805, 809 (Fed. Cir. 1986). See Ex parte C, 27 USPQ2d 1492, 1499 (Bd. Pat. App. & Inter. 1992) (Inventor sold inventive soybean seeds to growers who contracted and were paid to plant the seeds to increase stock for later sale. The commercial nature of the use of the seed coupled with the "on-sale" aspects of the contract and apparent lack of confidentiality requirements rose to the level of a "public use" bar.); Egbert v. Lippmann, 104 U.S. 333, 336 (1881) (Public use found where inventor allowed another to use inventive corset insert, though hidden from view during use, because he did not impose an obligation of secrecy or restrictions on its use.).

C.    Use by Independent Third Parties

  Use by an Independent Third Party Is Public Use If It Sufficiently "Informs" the Public of the Invention or a Competitor Could Reasonably Ascertain the Invention

Any "nonsecret" use of an invention by someone unconnected to the inventor, such as someone who has independently made the invention, in the ordinary course of a business for trade or profit may be a "public use," Bird Provision Co. v. Owens Country Sausage, Inc., 568 F.2d 369, 374-76, 197 USPQ 134, 138-40 (5th Cir. 1978). Additionally, even a "secret" use by another inventor of a machine or process to make a product is "public" if the details of the machine or process are ascertainable by inspection or analysis of the product that is sold or publicly displayed. Gillman v. Stern, 114 F.2d 28, 46 USPQ 430 (2d Cir. 1940); Dunlop Holdings, Ltd. v. Ram Golf Corp., 524 F.2d 33, 36-7, 188 USPQ 481, 483-484 (7th Cir. 1975). If the details of an inventive process are not ascertainable from the product sold or displayed and the third party has kept the invention as a trade secret then that use is not a public use and will not bar a patent issuing to someone unconnected to the user. W.L. Gore & Assocs. v. Garlock, Inc., 721 F.2d 1540, 1550, 220 USPQ 303, 310 (Fed. Cir. 1983). However, a device qualifies as prior art if it places the claimed features in the public's possession before the critical date even if other unclaimed aspects of the device were not publicly available. Lockwood v. American Airlines, Inc., 107 F.3d 1505, 1570-71, 41 USPQ2d 1961, 1964-65 (Fed. Cir. 1997) (Computer reservation system was prior art even though "essential algorithms of the SABRE software were proprietary and confidential and...those aspects of the system that were readily apparent to the public would not have been sufficient to enable one skilled in the art to duplicate the [unclaimed aspects of the] system."). The extent that the public becomes "informed" of an invention involved in public use activity by one other than an applicant depends upon the factual circumstances surrounding the activity and how these comport with the policies underlying the on sale and public use bars. Manville Sales Corp. v. Paramount Sys., Inc., 917 F.2d 544, 549, 16 USPQ2d 1587, 1591 (Fed. Cir. 1990) (quoting King Instrument Corp. v. Otari Corp., 767 F.2d 833, 860, 226 USPQ 402, 406 (Fed. Cir. 1985)). By way of example, in an allegedly "secret" use by a third party other than an applicant, if a large number of employees of such a party, who are not under a promise of secrecy, are permitted unimpeded access to an invention, with affirmative steps by the party to educate other employees as to the nature of the invention, the public is "informed." Chemithon Corp. v. Proctor & Gamble Co., 287 F. Supp. 291, 308, 159 USPQ 139, 154 (D.Md. 1968), aff’d., 427 F.2d 893, 165 USPQ 678 (4th Cir. 1970).

Even if public use activity by one other than an applicant is not sufficiently "informing," there may be adequate grounds upon which to base a rejection under pre-AIA 35 U.S.C. 102(f) and pre-AIA 35 U.S.C. 102(g). See Dunlop Holdings Ltd. v. Ram Golf Corp., 524 F.2d 33, 188 USPQ 481 (7th Cir. 1975). See MPEP § 2137 and § 2138.