Swarovski-Optik KG v Leica Camera AG & Anor

Patent claims are construed purposively and in the context of the specification, but deliberate claim limitations must retain meaning. For obviousness, the court must compare the complete inventive concept with the common general knowledge or the particular prior art, without hindsight. It is impermissible to identify a single feature, such as a negative lens, and then mosaic unrelated documents to reconstruct the invention. A patent is sufficiently disclosed where the skilled person can perform the invention across the claimed scope without undue burden or inventive skill. On the evidence, integrating a strong negative lens into the inverting system of a high-zoom riflescope, while maintaining a subjective field of view of at least 22 degrees at all magnifications, was neither anticipated nor obvious.

The claimant alleged infringement of a European patent concerning high-zoom sighting telescopes and riflescopes. The defendants challenged validity on construction, added matter, novelty, obviousness and insufficiency, relying principally on an IOR riflescope, Naumann, Betensky, Mai and Nikon. The court also determined whether the defendants’ three riflescopes fell within the claims. The central issues were the meaning of the claimed zoom factor, the position and integration of the negative lens, whether the IOR riflescope disclosed the invention clearly and unambiguously, whether the invention was obvious over the common general knowledge or individual prior-art references, and whether the patent enabled performance of the invention.

1. Construction. The claims were to be construed purposively and in context. “Maximum zoom greater than four times” meant a zoom factor greater than four, not a maximum magnification exceeding four. The inverting system had to contain the negative lens optically, with the lens positioned at the objective side of the second intermediate image and sufficiently separated from it. The 22-degree requirement meant that the subjective field of view had to be at least 22 degrees at every magnification.
2. Infringement. Leica’s riflescopes satisfied the central-tube and inverting-system requirements. A negative lens in the flared end of the central tube could still form part of the integrated optical system. The relevant zoom factors and focal lengths also fell within the claims.
3. Added matter. The application as filed disclosed, clearly and unambiguously, the possibility that one of two optical elements could remain stationary while the other moved relative to it. The amended claims therefore did not add subject matter.
4. Novelty. The IOR riflescope disclosed a zoom factor greater than four and used a powerful negative lens, but its lens was on the eyepiece side of the second intermediate image and was not integrated into the inverting system as claimed. Its field of view also fell below 22 degrees at ordinary minimum magnification. It did not clearly and unambiguously disclose the claimed combination.
5. Obviousness. Applying the four-stage approach in Pozzoli v BDMO, the relevant inventive concept was the complete claimed combination: a narrow central tube, an integrated strong negative lens in the inverting system, a zoom factor above four and a field of view of at least 22 degrees throughout the zoom range. The prior art and common general knowledge did not make that combination obvious. The defendants’ approach improperly began with the desired solution and worked backwards from field curvature. The IOR riflescope, Naumann, Betensky and Mai each differed materially in optical arrangement, purpose or technical context. Nikon added nothing material.
6. Sufficiency. Although the patent was general and contained few detailed specifications, the skilled person could create a riflescope meeting its requirements using the common general knowledge and routine design software. The claims were therefore sufficiently enabled.
7. The validity challenges failed and Leica’s riflescopes infringed. Further argument was reserved on the possible obviousness of claim 3, relief and costs.