EnOcean GmbH v Far Eastern Manufacturing Limited & Anor

For patent validity, a claim must be construed purposively in context, while giving effect to deliberate limitations in its language. A claimed “switch” requires an existing conducting path whose flow can be turned on or off; a generator that merely creates electrical power is not itself a switch. A “spring element” ordinarily denotes a physical mechanical element, not magnetic forces that perform an equivalent function.

For obviousness, the skilled person reads prior art with interest but without hindsight or an expectation that it supplies the answer. The age, commercial unattractiveness or technical limitations of prior art do not by themselves prevent it being a relevant starting point. The question remains whether the step to the claimed invention is technically obvious or requires invention.

EnOcean GmbH alleged that Far Eastern Manufacturing Ltd and TLC (Southern) Ltd infringed claims 1 and 3 of its patent for an electromagnetic energy converter used to power small wireless devices. The defendants accepted infringement but counterclaimed that the claims lacked novelty and were obvious over Harding, UK Patent No GB 879,938, and Goiran, European Patent Application No EP 0 836 166 A1.

By trial, the claimant accepted that claim 1 lacked validity over Goiran. The remaining issues concerned the construction of “an autonomous-power switch” in claim 1 and “a spring element” in claim 3, followed by novelty and obviousness over the two prior-art documents.

1. Construction. The claims were construed purposively in context. An autonomous-power switch is a switch component, distinct from the electromagnetic converter, which has its own power supply from that converter. A device that merely generates power when a button is pressed is not itself a switch. “A spring element” means a physical mechanical spring. Magnetic forces are not a spring element merely because they cause the moving element to return to its original position.
2. Harding. Harding disclosed the electromagnetic converter and the other relevant features of claims 1 and 3, but did not disclose integer 1.8 because its device was an electrical generator rather than an autonomous-power switch supplied by the converter. Nevertheless, the step from Harding to the use of its generator to power an autonomous switch would have been obvious. The skilled person would have regarded Harding as relevant prior art despite its age, its reference to dosimeters, and the possible size or voltage limitations of its device. Those matters might affect commercial desirability, but did not make the technical step inventive.
3. Goiran. Goiran disclosed the features of claim 1 but did not disclose the physical spring element required by claim 3. Its magnetic forces returned the moving core. Nor was it obvious to adapt Goiran by adding a mechanical spring. That would require departing from its teaching, introducing greater complexity and overcoming difficulties concerning the dead-centre mechanism and power generation. The proposed modification could be reached only with hindsight.
4. Disposition. Claims 1 and 3 were not anticipated by Harding or Goiran, and claim 3 was not obvious over Goiran. Claims 1 and 3 were, however, obvious over Harding. As no other claims were said to be independently valid, the Patent was invalid and liable to be revoked. The parties were directed to agree a draft order.

First-instance judgment. No prior appellate decision is stated in the judgment.