A Blog About Intellectual Property Litigation and the District of Delaware


Entries for tag: Doctrine of Equivalents

Representativeness is the bête noir of almost every § 101 motion. This is especially true early in the case, when the Court might rightly ask why it should bother invalidating 1 of 2,312,419 currently asserted claims.

This quandary is especially troublesome for defendants because it's often quite difficult to brief representativeness of a large number of claims in the necessary detail.

If you can tell me what claim 9 adds to to claim 8, I will literally eat my own cufflinks and then wear them again! Algorithm? More like Smellsbadgorithm!
If you can tell me what claim 9 adds to to claim 8, I will literally eat my own cufflinks and then wear them again! Algorithm? More like Smellsbadgorithm! AI-Generated, displayed with permission

Later in the case, things are a bit different. For one, there's a lot fewer claims at issue (hopefully) so knocking out just a few can make a big difference. Moreover, having a bit of discovery under your belt can make those representativeness arguments easier to make.

Caddo Systems, Inc. et al v. Jetbrains Americas, Inc., C.A. No 22-1033-JLH-LDH (D. Del. Feb. 25, 2025) (Report and Recommendation) had an interesting bit of argument along these lines that I hadn't seen before. The patents at issue there were all directed for a system to "allow a user to more easily navigate a file structure that may have many layers and options."

The parties disputed representativeness (quelle surprise!). One of the disagreements was whether certain claim limitations required a user to select (or have preselected) a menu item by different means. Plaintiff argued that these different means added something to claims that affected the § 101 analysis.

Unfortunately for plaintiff, their expert had submitted an expert report on the doctrine of equivalents, where he had opined that all of these different means actually performed the same function, in the same way, to reach the same result. Judge Hatcher, granting the motion for summary judgment, found this fact persuasive and cited it as an example of how the differences between the claims "do not prevent the Asserted Claims from being conceptually equivalent."

It's a possible contradiction that hadn't occurred to me before, and something to keep in mind when working with your own experts.

The doctrine of equivalents is often treated as the legal equivalent of going "c'mon....c'mon! its all the same."

whatsamatta you?
AI-Generated, displayed with permission

It's not uncommon to see it included in infringement contentions in terms that just note that, to the extent the noodlewiggler (TM) does not literally infringe claim 38 of of the '123 patent, it's insubstantially different, and performs the same function in the same way to achieve the same result, and is lame."

Judge Andrews issued an opinion today that neatly illustrates the problem with that tactic. The defendant in Carrum Techs., LLC v. Ford Motor Comp. C.A. No. 18-1647-RGA (D. Del. Nov. 9, 2023) (Mem. Op.) moved for summary judgment on the basis of a …