Swarovski's Marksman Hits The Right Target – Why Leica Should Define The Correct Problem To Be Solved

Swarovski-Optik KG v Leica Camera AG [2013] EWHC 1227.

Summary

At the Patents Court before Vos J, Swarovski-Optik brought patent infringement proceedings against Leica Camera, who challenged the validity of Swarovski's patent. The patent related to riflescopes. The judgment focused on the importance of identifying the skilled person and defining the correct problem for the skilled person to solve.

Background

A riflescope consists of an inverting optics system (relay) between objective and eyepiece optics systems. A first image is formed between the objective and inverting systems. A second image is formed between the inverting and eyepiece systems. The inverting system is needed for magnifying and flipping the image of the target being viewed, so that the target image is the right way up as seen through the riflescope. The image is formed over a curved surface, also referred to as field curvature, and the edges of the image can appear deteriorated.

Swarovski's patent was for a riflescope with a zoom factor above four and it enabled a field of view of at least twenty-two degrees at all magnifications. This was achieved by including a negative lens in the inverting system, where the negative lens causes beams to diverge and improves the edges of the image viewed, by curving the image formed over the curved surface towards the user.

Decision

Commercially available scopes for zoom factors above four were not produced at the relevant time of July 2005. Commercially available scopes generally showed a negative lens positioned on the eyepiece side of the second image, or less commonly coincident on the plane of the second image. An IOR riflescope had a negative lens located at the second image, for which the image plane moved towards the eyepiece as the target was viewed at increasingly closer distances. This meant that the negative lens could in some circumstances be located on the objective side of the image. Vos J did not consider this to form part of the normal use of the riflescope, since it would not usually have been used to view such close targets. Thus, the subject matter of claim 1 was not clearly and unambiguously disclosed in the prior art IOR riflescope so the claim was novel over this.

The common general knowledge highlighted that the most common position for a negative lens was on the eyepiece side of the second image.

Swarovski's negative lens was positioned on the objective side of this second image and was part of the inverting...