[GuestPost] Mending fences or moving goalposts? The fine line of patent amendments in Ensygnia v Shell

The IPKat has received and is pleased to host the following guest contribution by Katfriend Adanna Onah on a recent UK Court of Appeal decision concerning patent amendments and the limits of post-grant claim scope adjustments. Here’s what Adanna writes:

The Court of Appeal’s decision in Ensygnia IP Ltd v Shell UK Oil Products Ltd & Ors [2024] EWCA Civ 1490 spelled bad news for Ensygnia, whose patent on QR code-based authentication and payment systems was ruled invalid on multiple grounds. The ruling, delivered by Lord Justice Birss with Lady Justice Whipple and Lord Justice Phillips concurring, affirmed the High Court’s findings.

The Case at a Glance

The appeal concerned UK patent relating to graphical objects (GOs), such as QR codes, used for authentication and payment. Ensygnia, the patentee, alleged that Shell infringed its patent by using printed QR codes at petrol stations to facilitate mobile payments. While the trial judge agreed with Ensygnia’s construction of the claims and found that an earlier iteration of Shell’s system infringed, the patent was held invalid on three grounds: added matter, extension of scope, and obviousness over prior art.

Ensygnia appealed against the invalidity findings, while Shell cross-appealed on claim construction, arguing that the patent does not cover printed QR codes.

Claim Construction and a Question of ‘Display’ and ‘Signs’

A vital issue in the appeal was the interpretation of the term “display” and “sign” within Ensygnia’s patent. Ensygnia argued that its claims encompassed QR codes printed on static signs, such as posters or stickers, whereas Shell contended that the originally granted patent was limited to dynamically generated, electronic displays.

At first look, the phrase “display of a computing apparatus” seemed to point squarely at an electronic screen. After all, “display” is often a technical term, and the evidence suggested as much. Shell was understandably keen on this reading, arguing that the natural interpretation aligned with a computer screen rather than, say, a printed sheet stuck on a wall. The Court, however, was unimpressed by an overly literalist approach.

The judgment ultimately backed the trial judge’s reading: viewed in context, the patent specification made it clear that the ‘sign’ displaying the GO was not necessarily an electronic display at all, but could be a static, non-electronic sign, such as a piece of paper positioned near the lock. A result that might raise eyebrows among third parties hoping for a bit more clarity in claim drafting, but one that was, in the Court’s view, unavoidable given the wording of the amended version of the patent. In fact, the Court cautioned that “…it is worth noting, given what follows, that this conclusion depends on some specific wording in the passage of the description in the C2 specification.”

The Question of Extension of Scope

The second issue turned on whether amendments made to Ensygnia’s patent post-grant resulted in an impermissible extension of scope, thereby rendering the patent invalid under section 72(1)(e) of the Patents Act 1977. The law on broadening of claims after grant is straightforward. Section 76(3)(b) of the 1977 Act (mirroring Article 123(3) EPC) prohibits amendments that extend the protection conferred by a patent. If such an amendment is made, the patent is liable to be revoked.

The granted claim required that a GO be “displayed on a display of a computing apparatus,” which, on a natural reading, suggested an electronic display such as a computer screen. The amended claim, however, introduced the concept of a ‘sign’ and an “electronic door lock,” which had the effect of broadening the scope to cover a static sign, such as a piece of paper placed near the lock.

The Court rejected Ensygnia’s argument that the skilled reader would have understood the granted claim to cover such an arrangement from the outset. While claims are read in light of the specification, the granted specification did not suggest that a static sign fell within the claim. The key embodiments all depicted the GO on an electronic screen, and the specification contained references to other embodiments that were clearly outside the claim scope, indicating that not everything described in the specification was necessarily claimed.

By expanding the claim’s coverage beyond what was originally granted, the amendments contravened section 76(3)(b). As a result, the appeal was dismissed, and the patent remained invalid.

Added Matter: A Step Too Far

Another major pitfall for Ensygnia was the question of added matter. The Court reaffirmed the long-standing principle from Vector v Glatt Air Techniques [2007] EWCA Civ 805, stating that patent amendments cannot smuggle in new subject matter. The test is strict: amendments must be clearly and unambiguously derivable from the original application, without hindsight. Citing AC Edwards v Acme [1992] RPC 131, the Court noted that the distinction between “coverage” and “disclosure” is crucial. Thus, broad wording may cover multiple possibilities without necessarily disclosing all of them.

The original application primarily described an “electronic display” and although the word ‘sign’ appeared, there was no unambiguous indication that it referred to a non-electronic static sign.

Further, a passage in the application referred to periodic updates, which the Court interpreted as applying to both a “sign” and an “electronic display.” This reinforced the conclusion that any sign contemplated in the application must have been some form of electronic or digital device, not a static printed sign. As the amended patent specification introduced the concept of a static sign as a means to present the graphical object, the amendment added new subject matter.

Image credit: Imagen 3