the firm's post-grant practitioners are some of the most experienced in the country.


Artificial Intelligence (AI)
Artificial Intelligence (AI)
Digital Health
Digital Health
Energy & Renewables
Energy & Renewables

Fast Facts

About Our

Law Firm

About Our Law Firm

Headquartered within steps of the USPTO with an affiliate office in Tokyo, Oblon is one of the largest law firms in the United States focused exclusively on intellectual property law.

Get to know our


Get to know our History

Norman Oblon with Stanley Fisher and Marvin Spivak launched what was to become Oblon, McClelland, Maier & Neustadt, LLP, one of the nation's leading full-service intellectual property law firms.

Our Local and

Global Reach

Our Local and Global Reach

Outside the US, we service companies based in Japan, France, Germany, Italy, Saudi Arabia, and farther corners of the world. Our culturally aware attorneys speak many languages, including Japanese, French, German, Mandarin, Korean, Russian, Arabic, Farsi, Chinese.

A few of our


A few of our ACCOLADES

Oblon's professionals provide industry-leading IP legal services to many of the world's most admired innovators and brands.




From the minute you walk through our doors, you'll become a valuable part of a team that fosters a culture of innovation, client service and collegiality.

A few ways to

GET In Touch

A few ways to GET In Touch
US Office

Telephone: 703-413-3000
Learn More +

Tokyo Office

Telephone: +81-3-6212-0550
Learn More +


Patent Forms

Downloadable Patent Forms

The United States Patent and Trademark Office (USPTO) issued final rules implementing the inventor's oath or declaration provisions of the America Invents Act (AIA) on August 14, 2012.

Are you actually a Joint Inventor?

  • May 22, 2023
  • Article

Associated People

The Court of Appeals for the Federal Circuit (CAFC), on May 2, 2023, reversed the Delaware District Court’s decision in HIP, Inc. v. Hormel Foods Corp., that David Howard of Unitherm should be added as a joint inventor on US 9,980,498 (herein, the ‘498 patent), a patent owned by Hormel and directed to methods of precooking bacon and meat pieces. The decision on appeal considered whether Howard contributed to the conception of the invention and whether the determination of his joint inventorship should be upheld.

In 2005, Hormel and Van Doorn of Unitherm entered into a joint agreement to develop an oven to be used in a two-step cooking process. During this agreement, two different ovens were utilized for testing. One oven was an infrared oven and the other was a more conventional spiral oven. Howard claimed during these initial meetings that he disclosed the infrared preheating concept at issue on appeal. In 2008, Hormel conducted additional testing using Unitherm’s mini spiral test oven at Unitherm’s research facility upon leasing the oven from Unitherm. Subsequent testing at Hormel’s own facility resulted in a two-step cooking process being developed. The first step involved preheating the bacon and the second step involved cooking the meat in a superheated steam oven. Upon developing the process, Hormel filed a non-provisional patent on the two-step cooking process in August 2011.  The application issued in May 2018 as the ‘498 patent. The ‘498 patent named four inventors, who all assigned their interests in the patent to Hormel. 

In 2021, HIP sued Hormel in the District Court of Delaware claiming that Howard was either the sole inventor or a joint inventor of the ‘498 patent based on various claims. At the bench trial, the district court determined Howard was not the sole inventor, but that he was a joint inventor based solely on his alleged contribution of the infrared preheating in claim 5. The court stated that the infrared preheating concept in claim 5 was significant based on the differences between independent claim 1 and independent claim 5. The differences between claim 1 and claim 5 are shown below:

Claim 1: A method of making precooked bacon pieces using a hybrid cooking system, comprising:
Preheating bacon pieces with a microwave oven to a temperature of 140° F. to 210° F… .

Claim 5:    A method of making precooked bacon pieces using a hybrid cooking system, comprising:
Preheating bacon pieces in a first cooking compartment using a preheated method selected from the group consisting of a microwave oven, an infrared oven, and hot air to a temperature of at least 140° F… .

The district court determined that Howard was a joint inventor based on his contribution of the concept of preheating with an infrared oven identified in claim 5. This was corroborated by testimony from Van Doorn, pork loin testing date, and by three of the Hormel inventors stating they had not conceived of this particular element. The district court ordered the USPTO to add David Howard as a joint inventor on the ‘498 patent and to issue a Certificate of Correction accordingly.

On appeal to the CAFC, Hormel raised two issues.  Firstly, Hormel argued that the district court erred in determining Howard was a joint inventor because the alleged contribution of preheating with an infrared oven was well known and part of the state of the art. Hormel asserted that its claim to alternatively using an infrared oven was not significant when measured against the scope of the full invention. Secondly, Hormel contended that the court erred in holding that HIP met its burden of establishing by clear and convincing evidence that Howard is a joint inventor because Howard’s testimony was insufficiently corroborated.

The CAFC identified that inventorship is a question of law, reviewed without deference to the district court, and noted that the burden of proving that an individual should be added as an inventor to an issued patent is a heavy one, because the patent that issued creates a presumption that the named inventors are the true and only inventors, citing to Pannu v. Iolab Corp, 155 F.3d 1344, 1349 (Fed. Cir. 1998) and Garrett Corp. v. United States, 422 F.2d 874, 880 (Ct. Cl. 1970). As a result, an allegedly excluded inventor must prove a claim to joint inventorship by clear and convincing evidence.  e.g., Hess v. Advanced Cardiovascular Sys., Inc., 106 F.3d 976, 980 (Fed. Cir. 1997). Inventorship in the US has always been conception, but a test for sufficiency of the contribution to qualify in joint inventorshipcontests to that conception was set forth in Pannu, which the CAFC applied.  Pannu, 155 F.3d at 1351. The Pannu factors require that a joint inventor: (1) contributed in some significant manner to the conception of the invention; (2) made a contribution to the claimed invention that is not insignificant in quality, when that contribution is measured against the dimension of the full invention; and (3) did more than merely explain to the real inventors well-known concepts and/or the current state of the art.

Hormel argued that Howard (from HIP) did not satisfy factor (3) of the Pannu test, based on a prior printed publication, i.e., US 2004/0131738 A1 (Holm), that identified preheating pieces of meat with an infrared oven. Hormel argued that the district court erred by not taking into account this prior disclosure and only looking at the claim language to determine whether preheating with an infrared oven reflected the state of the art. Hormel additionally argued that Howard did not satisfy factor (2) of the Pannu test, stating that the district court’s finding that Howard was not the sole inventor clearly identifies that he did not contribute to the overall conception of the claimed method, but only suggested using a piece of equipment. Hormel noted that the specification of the ‘498 patent mentions “infrared ovens” only once, compared to “microwave ovens” mentioned multiple times, including the figures. Finally, Hormel argued that the infrared oven recitation in claim 5 does not make the ‘498 patent patentable, and therefore the recitation should not make the infrared oven contribution significant.

The CAFC agreed with Hormel’s argument regarding the second Pannu factor, thus not addressing the other arguments. The court held that Howard’s alleged contribution of pre-heating meat pieces using an infrared oven was “insignificant in quality” to the claimed invention given the frequency of microwave ovens in the description and drawings of the ‘498 patent.  The CAFC noted the single usage of “infrared oven” in the specification, as well as the single recitation in claim 5, determining that the use of a microwave was much more significant in determining the dimension of the full invention. The majority of the specification, the examples and corresponding figures for the preheating step employed a microwave oven, and not an infrared oven, according to the CAFC.  The HIP Court summarized that “the specification, claims, and figures all illustrate that Howard’s alleged contribution of preheating the bacon or meat pieces with an infrared oven is ‘insignificant in quality’ when ‘measured against the dimension of the full invention,’ … which squarely focuses on a preheating step using a microwave oven.” The CAFC did not need to visit the other Pannu factors, as a failure to meet any one factor is dispositive on the question of inventorship. Thus, the CAFC did not address HIP’s argument that Holm, describing a technique never described in a marketing or sales brochure or in a textbook, was too obscure to qualify as a well-known concept and/or the current state of the art, relevant to factor (3) in the Pannu test.


The decision in HIP, Inc. v. Hormel Foods Corp affirmed that the Pannu test is controlling law in determining qualification for joint inventorship.  The CAFC found it persuasive that the ubiquity in the written description of an undisputedly prior art technique, i.e., microwave heating, suffices to discount the claiming of a lesser known technique, i.e., infrared heating, likely because neither heating technique was itself necessary to the inventive concept of a first heating step to form a fat or grease barrier layer around the pre-cooked meat to reduce condensation and flavor dilution.  Ensuring correct inventorship for applications in joint inventorship situations may require considering the frequency in the description and drawings of an alternative claim element, particularly regarding a use of alternative prior art elements for achieving a result important to conception. In considering the second factor of the Pannu test and the issue of frequency, Howard's technique was “recited only once in a single claim ..., in a Markush group reciting a microwave oven, an infrared oven, and hot air,” whereas the other (two) independent claims “only recite[d] … preheating … with a microwave oven and d[id] not recite preheating with an infrared oven.” The CAFC will weigh the "significance," in the Pannu test, of an optional technique to the claimed invention substantially based on the frequency in the description and drawings, as well as recitation in the claims.