Battlekart Europe SA v Chaos Karts 1 Limited & Ors

For inventive step, the skilled person is ordinarily identified using the practical-interest formulation in Catnic. Where the claimed invention solves a problem in one established technical field by using a concept from a technically remote field, the Schlumberger approach may be required. The court may assess obviousness from the field of the problem, the field of the solution, or both. A problem-field team must consider whether the prior art suggests the invention or makes consultation with an expert in the solution field worthwhile. An invention lacks inventive step where either route would make the proposed combination obvious. A patent claim may itself disclose added matter. The claim in issue was invalid because the claimed combination was obvious over each of three items of prior art and because its wording extended beyond the application as filed.

Battlekart owned a patent for an extended-reality karting system combining real karts, projected images, tracking, server control and infrared emitters. The defendants marketed a competing system and accepted infringement of claim 11 if the claim was valid.

The defendants counterclaimed for invalidity based on lack of inventive step, absence of a technical contribution, and added matter. The court considered the proper skilled team, the relevant common general knowledge, three items of prior art, and whether claim 1G disclosed an emitter with at least two electromagnetic radiation sources of which only one was infrared.

1. Skilled team. The ordinary Catnic formulation identifies the person or team likely to have a practical interest in the subject matter. In inventive-step cases involving technically remote problem and solution fields, however, the skilled team may instead be drawn initially from the field of the problem or the field of the solution. The Schlumberger approach applies where use of a conventional Catnic team would unfairly broaden the common general knowledge. In the present case, the appropriate team was a Catnic team comprising systems, software and hardware expertise.
2. Remote technical fields. The problem-field team must read the cited prior art with care and interest. The court asks whether it would have contemplated the invention or regarded the solution concept as sufficiently promising to justify consulting an expert from the solution field. The converse analysis may also be undertaken. If either route makes the claimed combination obvious, inventive step is absent. A field relied upon for the analysis must have existed at the priority date.
3. Prior art and common general knowledge. BlackTrax and equivalent tracking systems formed part of the skilled team’s common general knowledge. It would have been obvious to try such a system to improve conventional karting, and selecting two or three infrared LEDs was a readily available option. Claim 11 therefore lacked inventive step over the Battlekart Disclosure, the MIT Disclosure and the Disney Application. The argument that the claim made no plausible technical contribution added nothing to the inventive-step case.
4. Added matter. The application as filed disclosed either one infrared source, at least two sources, or at least two sources all of which were infrared. It did not disclose at least two sources of which only one was infrared. On its proper construction, the words “sources comprising” qualified the sources collectively, not each source individually. Claim 1G therefore extended beyond the application as filed.
5. The Patent was invalid for lack of inventive step and added matter.