Swarovski-Optik Kg v Leica Camera Ag & Anor

Patent claims must be construed as a whole, using the specification and admissible evidence. The court should not impose uncertain wording absent from the claim. A dependent claim may duplicate an earlier claim because the usual assumption that it must be narrower is not inflexible. A functional result limitation can qualify the scope of a structural feature. For inventive step, it is insufficient to show that a skilled person might use a known component in a claimed region. The challenger must show that, without hindsight, the skilled person would arrive at the claimed combination and achieve the specified result. For novelty, a prior device must disclose every claimed requirement, including the required performance across all relevant magnifications.

Swarovski owned a European patent concerning a riflescope with variable magnification and a wide field of view. It brought infringement and revocation proceedings against Leica Camera AG and Leica Camera Ltd. The Chancery Division, Patents Court, held that the patent was valid and had been infringed.

Leica appealed, challenging the construction of claims 1 and 3, the findings on inventive step over common general knowledge and three cited technical disclosures, and the finding that the patent was novel over the IOR riflescope. Leica also sought permission to raise additional validity grounds on appeal. The central questions concerned the proper construction of the lens-positioning and field-of-view requirements, and whether the claimed combination was obvious or anticipated.

Floyd LJ delivered the judgment, with Kitchin and Sullivan LJJ agreeing. The appeal was dismissed.

1. Additional grounds. Permission to raise a new ground on appeal requires a realistic, rather than fanciful, prospect of success or another compelling reason. The court is slow to permit a point which was available but not taken at trial, particularly where further evidence might have been adduced and the respondent may suffer prejudice. Applying those principles, the proposed ambiguity and added-matter grounds were refused. The ambiguity argument did not approach the exacting threshold for a truly ambiguous claim: [2000] EWCA Civ 514, [2008] EWCA Civ 978 and [2005] FSR 23.
2. Construction. Claim 1 required the negative lens to be integrated into the inverting system, positioned at its eyepiece-facing end, but before the second intermediate image. Claim 3 did not enlarge claim 1. The canon that a dependent claim must narrow the scope of its parent is not inflexible, and claim 8 illustrated that claims may have identical scope. The claims did not require the lens to be a specified distance from the second intermediate image. They did, however, require the lens arrangement to achieve a subjective field of view of at least 22° at all relevant magnifications.
3. Inventive step. The inventive concept was not merely placing a negative lens somewhere between the zoom relay elements and the second intermediate image. It was placing the lens so as to obtain the specified wide field of view across the magnification range. Knowledge that a negative lens could reduce field curvature did not establish obviousness. Leica had to show that the skilled person, without knowledge of the patent, would have adopted the relevant position and achieved the claimed performance. The evidence did not establish that conclusion.
4. Prior art. Naumann disclosed a negative lens in a position associated with the eyepiece and did not teach the waist effect. Betensky concerned a materially different binoculars context and did not show how to design the claimed riflescope. Mai did not give a cogent reason for its lens positioning and would not have led the skilled person to the invention without hindsight. None rendered the patent obvious.
5. Novelty. The claim required the 22° field of view to be guaranteed at all magnifications at which the relevant intermediate image was projected into the eyepiece-end image plane. The IOR riflescope fell below 22° at lower magnifications and therefore did not anticipate the claims. It was unnecessary to decide whether unusual adjustment conditions could be postulated for novelty; the court observed that the permissibility of such an approach was questionable.

The appeal was dismissed.

1. Court of Appeal (Civil Division): appeal dismissed; permission to raise additional grounds refused. [2014] EWCA Civ 637.
2. Chancery Division, Patents Court: Vos J held the patent valid and infringed.