Improper Inventorship Case Shows Why Patents Need Perfection

While perfection is a standard not often achieved, a recent appeals court decision in Fortress Iron, LP v. Digger Specialties, Inc. stressed that the inventorship listed on a patent demands perfection. In Fortress, the US Court of Appeals for the Federal Circuit affirmed the invalidity of two patents because of incomplete inventorship that couldn’t be corrected.

The decision confirms that improper inventorship remains a defense to patent infringement liability—since a patent is invalid if it fails to list the correct inventors—and provides insights for both patent holders and those accused of infringement.

Case Background

Fortress’ inventorship issues arose years after its patents for vertical cable railing panels were issued and only when it sued a competitor, Digger Specialties Inc., for infringement. Fortress’ owner had conceived of the inventions but struggled to develop a prototype. Employees at a Chinese contract manufacturer proposed changes, but they weren’t named as co-inventors on the patents.

Digger argued that the Chinese employees contributed to the inventions and should be named inventors. Though Fortress agreed, it couldn’t locate one of them. It amended a pending patent application to include the missing inventors, but when it attempted to correct the already-issued patents under 35 U.S.C. Section 256—which allows for the correction of inaccurate inventorship—Digger objected because Fortress failed to notify all co-inventors.

In response, Fortress argued that it could amend inventorship without notifying the missing inventor because the inventor wasn’t a “concerned” party under Section 256 as he had no economic interest in the patents. Fortress also argued that Congress eliminated the requirement for perfect inventorship, removing this as a ground for invalidity. Digger disagreed, arguing that the requirement still existed and that an inventor is a concerned party, regardless of whether that individual has any property rights in the invention. A district court agreed with Digger, explaining that unless Fortress could notify the missing inventor, Fortress couldn’t amend the named inventors. Fortress then appealed, raising the same arguments.

The Federal Circuit panel rejected Fortress’ arguments, reaffirming that improper inventorship remains an invalidity defense. It also explained that “all parties concerned” includes all co-inventors, regardless of whether they have an economic interest in the patent.

Why This Matters

The panel’s decision in Fortress highlights critical steps that patent holders can take to protect their patent rights and potential areas of attack for those accused of infringement.

For innovators, the decision underscores the importance of robust inventorship analyses and proper documentation at every step when developing any patentable subject matter. Companies should have clear policies in place to document all contributions to the invention, including any problems that may have occurred during development, and who contributed to the solutions to overcome those problems.

These policies should require detailed records that can inform the inventorship in a patent application and can be properly corroborated in the event of a challenge. For example, laboratory notebooks should be dated and witnessed, and data should be clearly labeled with the experiment to which it relates. Any documentation should be detailed enough to allow for the identification of who contributed to any aspect of the resulting invention. Innovators must also consider contributions from non-employees and coordinate with their partners, especially contract researchers and manufacturers, to ensure a similar level of documentation.

Clear documentation can prevent inventorship issues from arising years after the original application. For example, because an invention is defined by the limitations presented in the patent claims, later claims with new limitations may incorporate ideas from an inventor who wasn’t originally listed. As long as the applicant seeks to correct the inventorship listing before the patent is issued, they can petition the Patent Office to add missing inventors without involvement from all inventors. Fortress took advantage of this process during its litigation to obtain a third patent with the correct inventors.

The circumstances in Fortress also highlight the importance of maintaining contact information for those who contribute to any projects. If Fortress had been able to notify the missing inventor, the decision may have been different. To guard against this scenario, companies should have policies in place to retain consistent contact information. Companies can consider employment contract provisions that require employees to provide reliable contact information when departing. They can also consider coordinating with their contractors to ensure similar contact information is maintained. Ultimately, companies should work with prosecution counsel early and often to address inventorship issues.

Patent challengers, on the other hand, now have confirmation that inventorship remains a viable invalidity defense. When contesting validity, challengers should seek discovery of development documents and inventor testimony early in the process and map out inventorship for each part of each claim. Challengers should also be mindful of the differing burdens here. While the patentee must notify each co-inventor under Section 256, the challenger only needs to show a flaw in the list of inventors. It may be sufficient in certain cases for the challenger to show that some unknown individual should have been listed on the patent but isn’t. Notably, it isn’t the challenger’s burden to locate missing inventors.

Fortress illustrates the risks and opportunities that arise from incorrect inventorship. By being diligent, patent holders, challengers, and investors can position themselves to prevail on this issue.

This article does not necessarily reflect the opinion of Bloomberg Industry Group Inc., the publisher of Bloomberg Law, Bloomberg Tax, and Bloomberg Government, or its owners.

Author Information

Linnea Cipriano is a partner in Goodwin’s Intellectual Property Litigation practice.

Timothy J. Beavers is an associate in Goodwin’s Intellectual Property Litigation practice.

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