UK: The Entire Claim Rule Applies to Independent Claims Presented in Two-Part EPO Format

The English High Court has recently held that in accordance with Section 125 of the Patents Act 1977 (English domestic law), an invention is defined by the whole claim, as interpreted by the description and any drawings. The Court further held that the protocol on interpretation, Article 69 of the European Patent Convention, applies for this purpose and that a limitation has no less weight merely because it appears in the pre-characterising part of an independent claim cast in a two-part format. Storage Computer Corp. UK Limited v. Hitachi Data Systems Ltd., Case No. HC 01 No. 0101244, English High Court (August 21, 2002).

According to an approach preferred by the European patent office, independent claims are frequently cast in a two-part format, with the first part setting out features known from the closest prior art and the second part reciting novel features of the invention. The first part is called the "pre-characterising" part, and the second part is called the "characterising part." The protocol on interpretation states that claims should not be interpreted to limit the scope of protection by the strict, literal meaning of the words used in the claims, the description and drawings being employed only for the purpose of resolving ambiguity in claim language. Neither should claim language be interpreted as a mere guideline, the actual scope of protection extending to that contemplated by a patentee based on a consideration of the description and drawings by a skilled person in the art. Instead, claims are interpreted as defining a position between these extremes to provide a fair protection for the patentee and a reasonable degree of certainty for third parties.

Storage Computer brought infringement claims under two European patents against Hitachi Data Systems. The independent claims of the first patent were in the conventional two-part European format and included various limitations in the pre-characterising portion. The parties agreed that Hitachi did not "literally" infringe the claim. However, Storage Computer argued that in accordance with the protocol on interpretation of Article 69, the unsatisfied limitation should be disregarded because it did not relate to the "real" invention. In other words, Storage Computer conceded that Hitachi did not literally infringe the claim but argued that since the limitation relied upon by Hitachi for its non-infringement defense appeared only in the pre-characterising part of the claim (acknowledged to be old), rather than the characterising part of the claim that defines the invention, infringement should be found nonetheless.

The Court found the invention to be defined by the whole (both characterising and pre-characterising portions) claim when properly construed. The Court noted that in balancing the interests of the patentee and the public, it must give due weight to the fact that the specification excludes variants from that which is contemplated by the claims, and further noted that in the present case the description contained no examples of an embodiment where the limitation Storage Computer argued should be disregarded was not present. The Court also gave apparent weight to evidence that the alleged infringement (operating without the limitation in issue) performed significantly better in several key respects.

Disclosure: In the interests of full disclosure, we note that the London office of McDermott, Will & Emery represented Hitachi Data Systems in connection with the matter reported above.