The Top Line
The Federal Court found that claims of three water slide patents were invalid for being broader than contemplated by the inventor. This is an interesting decision because there are few, if any, examples in Canadian patent law where overbreadth is the primary or sole independent ground of invalidity. Furthermore, the focus of this decision on what the inventor “contemplated” appears to introduce an element of subjectivity into the test of overbreadth.
In Proslide Technology v Whitewater West Industries, 2024 FC 1439 – an infringement action between two competing water slide companies – the Federal Court held that claims in three of the patents at issue were invalid as being broader than the invention “contemplated” by the inventor.
This is a precedent-setting decision in that it is among very few Canadian cases decided on the basis of the “claims broader than invention made” branch of the overbreadth test. Further, the trial judge arguably expanded the test and admissible evidence relating to invalidity by focusing the analysis on what the inventor “contemplated” during the work that led up to the invention.
Context on Overbreadth
In general, under Canadian law, a patent claim may be invalid if it is broader than the invention made or disclosed. If an element that is essential to the invention is omitted from the claims, then those claims are said to be invalid for claiming more than what the inventor has given to the public. However, this ground of invalidity does not often succeed, and is almost always pleaded with other grounds of invalidity.
It has been suggested that the doctrine of overbreadth is redundant in that the harms it is meant to address would typically fall under one or more other grounds of invalidity such as insufficiency of disclosure, obviousness, or inutility. The significance of the Proslide case is that the Court found the overbroad claims at issue were not obvious and were useful (insufficiency was not at issue), making it a rare example where overbreadth was not redundant or obiter.
The Patents at Issue
The three Proslide patents which were invalid (in part) for overbreadth were from a family of patents titled “water ride” and which claimed a “slide feature for an amusement ride adapted to carry a rider or ride vehicle sliding thereon”, with various elements relating to the orientation, geometry, and physical features of the sliding surfaces and walls of the slide. Most of the claims were not limited to “water slides”, but referred to “amusement rides” generally. A narrower dependent claim included the “water slide” limitation.
Although a number of invalidity grounds were raised by the defendant (WhiteWater), the Court found that these three patents were not invalid for obviousness and that utility was soundly predicted. As such, the focus of the invalidity was overbreadth. Moreover, WhiteWater did not allege that the claims were broader than the disclosure, but only alleged that the claims were “broader than the actual invention made”. The Court interpreted the legal test as asking whether the claims were broader than the invention made or contemplated by the inventor.
Evidence to Establish Overbreadth
In the factual analysis, the Court focused on oral testimony given by the inventor, as well as expert evidence opining on minutes from design review meetings, design specification documents, and emails between the inventor and his colleagues. Based on this evidence, the Court determined that there were certain key elements “contemplated” by the inventor during the design of the invention underlying the three patents which were not present in the claims. Among various elements, the Court specifically pointed out the inventor’s testimony that he envisioned the invention as a water slide rather than for amusement rides generally.
The focus on inventor testimony about what he contemplated and the reliance on correspondence and meeting minutes introduces a subjective component into this ground of invalidity. The trial judge acknowledged this in preferring the defendant’s expert evidence relying on the inventor’s documents over the plaintiff’s expert, who did not.
A fourth patent at issue was also alleged to be invalid for overbreadth because nothing was ever made by the inventor. However, the Court found that the defendant had not met their burden of proof in respect of this patent because the invention is not limited to only what was physically built, but also what was contemplated. The defendant’s expert testimony was rejected on this patent because it focused on what was built.
Conclusion and Takeaway
In conclusion, it appears that following ProSlide, the Court is to ask what a skilled person would consider as key aspects of the invention(s) contemplated or made by the inventor (see ProSlide at para 251) including on the basis of inventor testimony and inventor documents.
This formulation of the overbreadth test may raise interpretive issues in subsequent cases, as it is not clear from ProSlide when the inventor ought to have contemplated the invention, what would happen if there were two or more inventors, and how the Court should deal with scenarios when the expert disagrees with the inventor on what the “key aspects” are.
We expect that, if appealed, further guidance may be expected from the Federal Court of Appeal on this issue. Overbreadth was last addressed in Seedlings Life Science Ventures v Pfizer, 2021 FCA 154, where the FCA held that overbreadth was an independent ground of invalidity, but did not deal with the “broader than invention made” branch of the test.
Nisha Anand gave a presentation on this topic at the 2024 University of Toronto Patent Colloquium.