The recent High Court decision in Ensygnia v Shell ([2023] EWHC 1495 (Pat)) is highly relevant to the ongoing controversy of claim interpretation and description amendments (IPKat). In Ensygnia v Shell, Miss Charlotte May KC (sitting as Deputy Judge in the High Court of England and Wales) considered how a post-grant amendment which added the phrase that certain embodiments “fell outside the scope of the claims”, might affect claim interpretation. The Deputy Judge found that this statement changed the natural reading of the claim language in added matter and infringement analysis. The decision in Ensygnia v Shell is a fresh warning, if one was needed, of the substantial risks of description amendments. 

Case Background – Ensygnia v Shell

Customer recognition

Ensygnia sued Shell for infringement of their UK patent (GB 2489332 C2). Shell counterclaimed that the patent was invalid. The patent related to a method for identifying whether a user was authorised to access a service. Claim 1 specified a method comprising a user using their phone to scan “a graphical encoded objection” (e.g. a QR code) “displayed on a display of a computing apparatus”. The alleged infringement was Shell’s petrol station app which allowed registered customers to purchase petrol using their phone and a QR code displayed on a card at the pump. 

The Patentee had amended the description and claims of the patent post-grant (Section 27, UKPA). Particularly, the Patentee amended the claims to specify that the “display” of the computing apparatus displaying the e.g. QR code was a “sign”. The Patentee also amended the description to state that some of the embodiments and figures were “outside the scope of the claims”, ostensibly to bring the description in line with the amended claims (see amended page 22 of the description). 

Legal Background: Principles of claim interpretation

Article 69 EPC provides that the extent of protection of a European patent “shall be determined by the claims. Nevertheless, the description and drawings shall be used to interpret the claims“. The UK courts have interpreted Article 69 EPC as permitting a construction of the claims that takes account of the inventor’s purpose as indicated in the description and drawings of the patent. However, purposive construction does not allow an obviously deliberate limitation in the claims to be ignored. Accordingly, as recently summarised by Lord Justice Arnold, the three key considerations for claim interpretation in the UK are 1) the wording of the claim, 2) the context provided by the specification and 3) the inventor’s purpose (InterDigital v Lenovo [2023] EWCA Civ 105). 

The UK approach to claim interpretation under Article 69 EPC contrasts with the EPO’s approach. Recent Boards of Appeal have emphasised that the description and figures of a patent should only be referred to when the natural meaning of the claim language is unclear (IPKat) (see also the “catastrophic comma loss cases”, IPKat).

Construing the claims in view of the description

The Deputy Judge applied the principles of construction to the word “sign” as used in the claims. Ensygnia argued that the “sign” specified by claim 1 related to a non-electronic static sign, and therefore included in its scope the paper QR codes used by Shell. Shell argued that their petrol pump app did not infringe the claim because the “sign” specified in the claim should be understood as being limited to an electronic display on a computer screen. 

The Deputy Judge looked to the description and the inventor’s purpose to understand how the term “sign” should be understood. Under a natural reading, the Deputy Judge agreed that the sign on a display forming part of a “computing apparatus” would generally be understood to be an electronic one (para. 152). However, the description of the patent had been amended by the Patentee post-grant to specify that a particular embodiment having an electronic display was “outside the scope of the claims”. In view of this passage, the Deputy Judge agreed with Patentee’s interpretation that the “sign” specified in the claim did not have to be an electronic display. Applying the principles of claim interpretation, the Deputy Judge concluded that “since the patentee has deliberately limited the claim to a display on a sign, this limitation cannot be disregarded even though it conflicts with some of the teaching of the Patent and does not provide all the advantages of the invention that an electronic display would bring” (para. 154). 

Added matter & extended protection

Unsurprisingly, Shell argued that the post-grant description and claim amendments added matter and extended the scope of protection of the patent. In the interests of legal certainty, post-grant amendments must not increase the scope of protection of a granted patent. 

For the Deputy Judge, the added statement that the embodiments comprising an electronic display were “outside the scope of the claims”, was critical to the interpretation of “sign” in the claims as including non-electronic signs: “Without hindsight, I do not think it would even occur to the skilled reader reading this passage in the context of the application as a whole that the invention could be implemented using a sign that is not electronic or which cannot be changed.” (para. 177). The Deputy Judge thus agreed with the Defendant that the statement “outside the scope of the claims” added matter to the application as filed and also extended the scope of protection beyond the patent as granted. The Deputy concluded that the patent should thus be revoked for added matter and extended protection. 

The Patentee in this case therefore found themselves stuck in an added matter/claim construction squeeze; the claim construction required to cover the alleged infringement (introduced by the Patentee post-grant) was also the claim construction that added matter. 

Final thoughts

In this case, the description amendment was critical for claim interpretation. The Patentee had changed the meaning of the claims by the back-door of description amendments. Such an approach is unlikely to be successful in view of the added matter/claim construction squeeze. None-the-less, the Ensygnia v Shell is a timely reminder of the potential danger of description amendments dictated by the patent office. 

The EPO Guidelines for Examination currently state that “[a]ny inconsistency between the description and the claims must be avoided if it could throw doubt on the subject-matter for which protection is sought and therefore render the claim unclear”. Specifically, according to the Guidelines “[t]he applicant must remove any inconsistencies by amending the description either by deleting the inconsistent embodiments or marking appropriately so that it is clear that they do not fall within the subject-matter for which protection is sought” (F-IV-4.3). 

There has been long-standing concern that the description amendments currently required by the EPO based on these Guidelines could affect the interpretation of the claims in doctrine of equivalent analysis. Ensygnia v Shell highlights that including statements that exclude certain embodiments from the scope of the invention may even affect claim interpretation in purposive construction. A difference between interpretation of the claims pre-grant and post-grant may then invalidate the patent for added matter. This danger is further compounded by the different approach taken by the EPO Boards of Appeal and the UK courts to claim interpretation under Article 69 EPC. 

We are now awaiting to see if a Board of Appeal will refer the issue of description amendments and claim interpretation to the Enlarged Board of Appeal (EBA) (IPKat). In the meantime, wise applicants will take care with their description amendments. 

Further reading

Claim interpretation

Description amendments