Infernal Technology, LLC v. Activision Blizzard Inc.

Case No. 2021-2349

Decided: January 24, 2023

The Federal Circuit issued a decision on January 24, 2023 stating that a collection of Activision Blizzard’s video games did not infringe two patents that dealt with methods of lighting computer graphic scenes in video games. The Federal Circuit’s decision turned on a dispute over claim construction and a question of “antecedent basis,” which is the general principle that language in a patent claim that refers back to an element introduced earlier in the claim should be read as being the same element. This is a common issue in patent cases, and is why patent claims use language like “said item” (though recently “said” has fallen out of fashion, replaced by “the item”).

The case arose when Infernal Technology, LLC (“Infernal,” joined by a second company, Terminal Reality Inc.) sued industry giant Activision Blizzard for allegedly infringing two patents, US Patent No. 6,362,822 (the ’822 patent) and US Patent No. 7,061,488 (the ’488 patent). Both patents dealt with—and were in fact titled—“lighting and shadowing methods and arrangements for use in computer graphics simulations.” Infernal argued that 19 games produced by Activision Blizzard infringed the lighting and shadowing methods described by the ’822 and ’488 patents, including multiple titles in the Call of Duty series, the Destiny series of games, an expansion game to the MMO World of Warcraft, and several games under the Skylanders title.

The central issue of the case was Infernal’s interpretation of a definition of “observer data” in the claims of the ’822 patent (which the Federal Circuit deemed applicable to the ’488 patent as well). Claim 1 of the ’822 patent recited “providing observer data of a simulated multi-dimensional scene,” and later in the claim recited “combining at least a portion of [a] light accumulation buffer with said observer data.” The first issue in a patent infringement case is to figure out what the terms mean. The District Court which first heard Infernal’s case interpreted “observer data” to mean “data representing at least the color of objects in a simulated multi-dimensional scene as viewed from an observer’s perspective,” an interpretation both parties agreed with. Essentially, this definition limited the scope of the technology at issue to the concept of combining two things. First, data representing what a player of a game would see on the screen (the “at least the color of objects in a simulated multi-dimensional scene,”) and second, a process for lightening pixels on a screen using “said observer data” and a “light accumulation buffer.”

The Activision-Blizzard games provided “observer data” that met the District Court’s definition of “providing observer data of a simulated multidimensional scene,” the first mention of “observer data” in the claims. However, the source code controlling the games later combined a narrower set of the observer data with a “light accumulation buffer.” To address this, Infernal argued that the “said observer data” the ’822 patent combines with the light accumulation buffer could be a narrower set of the observer data. In essence, Infernal argued that the “said observer data” mentioned in claim 1 did not need to refer to the exact same set of “observer data” mentioned earlier in the claim.

For example, argued Infernal, the first mention of observer data (“providing observer data”) might refer to multiple different types of data relating to what the player might see on the screen, such as albedo (color data), normal vector, position, depth, and other data. But, argued Infernal, the observer data combined with the light accumulation buffer (“said observer data) might be a narrower subset of observer data. For example, this second reference to observer data might refer only to the albedo/color of objects displayed on a screen. If the “said observer data” could refer to a narrower subset of the earlier-mentioned observer data, then Activision-Blizzard’s games would infringe Infernal’s patents.

Unfortunately for Infernal, the District Court held—and the Federal Circuit agreed—that because the claim used the phrase “said observer data” in the later mention to observer data, the claim must be referring to the same observer data in the earlier-mentioned “providing observer data” step. This is the concept of “antecedent basis” mentioned above, which basically means that where a term in a claim refers to an earlier use of the term, both instances must have the same meaning. Additionally, because the ’822 patent’s claims also refer to “a portion of the observer data,” the Federal Circuit agreed with the District Court’s construction that the “said observer data” must refer to the entire set of “observer data” initially provided. As a result, because the accused Activision games combined a narrower set of observer data with the light accumulation buffer than the set of observer data that was initially “provided,” Infernal failed to show the Accused Games infringed the claims of the ’822 and ’488 patents. The Federal Circuit affirmed a motion for summary judgment on behalf of Activision Blizzard, granting them victory in the case.

This case serves as a reminder that, as always, the claim is the most important part of the patent and claim language is going to be read for what it says.  Careful claim drafting is important when preparing and prosecuting a patent.  But also important is considering potential future infringers and how to claim the invention in a manner that avoids creating opportunities for design arounds.

Check back here for future posts about game related lawsuits and patents!

Thanks to John Peloquin for preparing this case summary.