Processing All Things Federal Circuit
April 25, 2023 - Last Week in the Federal Circuit

Last Week In The Federal Circuit (April 17 – April 21): Inherent Limits And Patent Enablement

Optical Cables

We’re still waiting for the Supreme Court to issue its decision in Amgen v. Sanofi. But in the meantime, the Federal Circuit continues to provide insights into 35 U.S.C. § 112’s requirement to “enable” persons of skill in the art to “make and use” a claimed invention.

Case of the week: Inc. v. ITC, No. 22-1228

Panel: Chief Judge Moore and Judges Prost and Hughes, with Chief Judge Moore authoring the opinion

You should read this case if: you have a case involving enablement of a claim with an open-ended range

Whether people realize it, fiber optics—hair-thin strands of glass used for transporting light—are everywhere. They form the backbone of the internet and are also used for interconnecting servers in data centers throughout the world. 

Corning Optical Communications owns several patents to housings for fiber optic connection equipment. The housings connect large numbers of fiber optic cables. But the claims did not specify exactly how many connections were supported, instead reciting only a lower limit, such as that the housings support “a fiber optic connection density of at least ninety-eight (98) fiber optic connections per U space.” (A “U space” refers to the space for a standard server rack unit, such as in a data center.) 

After Corning successfully obtained an ITC exclusion order based on these claims, the respondent appealed to the Federal Circuit. It argued that the patents failed to enable these open-ended claims because the patents taught at most how to make and use housings supporting 144 fiber optic connections per U space but the claims cover an unlimited upper range of connection densities.

The Federal Circuit affirmed the ITC’s decision upholding the challenged claims. The Court explained that it has often applied a two-part standard for claims with open-ended ranges: such claims are enabled “if [1] there is an inherent, albeit not precisely known, upper limit and [2] the specification enables one of skill in the art to approach that limit.” Whether a skilled artisan would understand there to be an upper limit “is a question of law based on underlying factual findings.”

The Court agreed with the ITC’s determination that skilled artisans would understand Corning's claims to have an inherent upper limit of “about 144 connections per U space.” That conclusion followed from the ITC’s well-supported finding that densities “substantially above 144 connections per U space were technologically infeasible” at the priority date. The patents’ shared description disclosed that the maximum achievable density at the time was 144 connections per U space. And expert testimony confirmed the same. 

Given this evidence, the Court agreed with what it viewed as effectively a claim construction that the claims “cover only connection densities up to about 144 connections per U space” and “exclude higher densities.” The Court thus affirmed because there was no dispute that the claims were enabled if limited to about 144 connections per U space.


Precedential opinions:  6

Non-precedential opinions:  3

Rule 36: 0

Longest pending case from argument: Spence v. McDonough, No. 22-1105 (73 days)

Shortest (non-Rule 36) pending case from argument: Cioffi v. Google LLC, No. 18-049 and DivX, LLC v. Netflix, Inc., No. 22-1481 (tied for 12 days)