Tate & Lyle Technology Ltd v Roquette Freres

A European patent claim must be construed purposively and contextually by the skilled reader, using the description and drawings to balance fair protection with reasonable legal certainty. The claim is read as a whole, without strict literalism or an expansive meaning based solely on the proprietor’s hoped-for monopoly. A claim to using a substance to control a product’s form may include checking that the relevant content is already suitable, so that no adjustment is made. Control may also operate through a precursor before a later chemical process. Whether a claim is novel or anticipated informs construction but does not determine it; prior art mentioned in the specification may still anticipate the claim.

Roquette Frères held European Patent (UK) No 0 905 138 for a patent concerning the crystallisation of maltitol. Its surviving claim concerned the use of maltotriitol to modify or control the form of maltitol crystals.

Lewison J declared the patent invalid and revoked it, holding that it was anticipated by prior art. He rejected the alternative obviousness case and also considered that the patent amounted to a discovery: [2009] EWHC 1312 (Pat). Roquette appealed on construction, anticipation and discovery. Tate & Lyle served a respondent’s notice on obviousness, but that issue did not need to be argued. The central issue was the proper construction of the surviving claim.

Lord Justice Lloyd gave the leading judgment, with Richards and Sullivan LJJ agreeing. The appeal was unanimously dismissed.

1. Construction framework. Under article 69(1) of the European Patent Convention and article 1 of the Protocol on the interpretation of article 69, the claim had to be construed by the skilled reader in the context of the patent as a whole. The description and drawings were relevant to interpretation. The construction had to balance fair protection for the proprietor with reasonable legal certainty for third parties. It required a purposive and practical approach, avoiding both strict literalism and an expansive meaning based on what the proprietor might have contemplated.
2. Meaning and scope of the claim. The patent taught that the form or habit of maltitol crystals was a function of the maltotriitol content of the material subjected to crystallisation. The claim therefore covered using that content to obtain the desired crystal habit. Control could involve adjustment before hydrogenation, applied to maltotriose, or after hydrogenation, applied to maltotriitol. It could occur during initial crystallisation or recrystallisation. The court was content to assume that use of maltotriose as the precursor of maltotriitol fell within the claim.
3. No adjustment necessarily required. The detailed description, including the reference to depletion of maltotriose “or not at all”, the process at [0072], and the sole illustrative example, showed that the claim did not necessarily require an alteration of the relevant level. It included a process in which analysis established that the maltotriitol content was already suitable and no adjustment was made. The word “use” did not require an active alteration in every case.
4. Other matters. The surviving claim had to be construed on its own terms. The parties’ or the European Patent Office’s statements in the opposition proceedings were not helpful to that exercise. The court also confirmed that prior art referred to in a specification could still anticipate a claim; novelty did not determine construction. Since the construction issue disposed of the appeal, the court did not decide the remaining anticipation, discovery or obviousness issues.

1. Court of Appeal (Civil Division): The appeal was dismissed on the construction issue. The remaining issues on the appellant’s notice and the respondent’s notice did not require determination: [2010] EWCA Civ 1049.
2. High Court, Chancery Division, Patents Court: Lewison J declared European Patent (UK) No 0 905 138 invalid and ordered its revocation, holding it anticipated by prior art: [2009] EWHC 1312 (Pat).