Defendant pokes holes in screen patent claims

In Effe v Stiltende Genius the Court of Milan denied injunctive relief under the doctrine of equivalents to a plaintiff which tried to base an infringement claim on the subject matter which was explicitly disclaimed in the background section of its patent. In its decision the court, following a line of established case law, emphasised that the patent specification represents the essential starting point for determining the correct weight to be ascribed to features claimed in the pre-characterising portion of a claim.

According to prevailing Italian case law, a patent is infringed under the doctrine of equivalents if the accused product, despite not falling within the literal scope of protection of the claims, represents a variation of the claims that is obvious to a person skilled in the relevant field. In addition, the assessment of infringement under the doctrine of equivalents typically gives  little weight to features found in the pre-characterising portion of an independent claim.

Plaintiff Effe Srl sought injunctive relief against Stiltende Genius Srl for infringement of European Patent 1905944 B1 ('EP’944'). EP’944 claimed a roller screen device (a device in which the screen was used as a mosquito net), with one fixed upright and one slidable upright. A screen was provided between the two uprights.

The pre-characterising portion of the independent claim specified that there was a roller inside a slidable upright, around which the screen could be wound or unwound. Meanwhile, a fixed upright contained guiding elements for the screen. The characterising portion of the claim related to special technical features of the guiding elements, which the European Patent Office (EPO) acknowledged to be inventive.

The mosquito screen device produced by Stiltende included the characterising special feature of the invention, but differed from the claim in that it used the opposite arrangement: the guiding elements were in the slideable upright and the roller was inside the fixed upright.

Effe argued that even if there were no literal infringement, the accused product infringed the claim under the doctrine of equivalents, since the characterising special feature was present in the accused product and the accused product differed from the claim only in the positions of the two components defined in the claim’s pre-characterising portion.

Stiltende argued that there was no infringement under the doctrine of equivalents because the background section of the patent specification clearly stated that:

  • roller screen devices comprising a roller in the fixed upright were known; and
  • it was an object of the invention to provide a solution in which the roller was in the slidable upright.

The prior art search by the EPO also revealed that roller screen devices comprising a roller in the slideable upright were known. As a result, the applicant limited the claims to the above-mentioned characterizing features involving particular improvements to the guiding elements.

The Court of Milan found that EP’944 was valid, but not infringed by the accused product. The court noted that the accused product included the characterising improvements of the guiding elements, but did not include some of the pre-characterising features. Roller screen devices with the roller in the fixed upright were well known to persons skilled in the field as alternative solutions to devices in which the roller was placed in the slidable upright.

The court stressed that it was essential to ascertain carefully whether the patent specification supported the extension of the scope of the claims to these alternative solutions. Since in the background portion of the description such alternatives were explicitly disclaimed and described as prior art, the court reasoned that there was no support for such extension and thus the patent could not be infringed under the doctrine of equivalents.

The plaintiff requested reconsideration, but the court refused the request and again denied injunctive relief.

The Court of Milan has confirmed that subject matter in the background section of a patent specification describing the prior art is disclaimed by the patentee and cannot be recaptured under the doctrine of equivalents to expand the scope of the claims. The decision is similar to US Federal Court decisions which have applied the disclosure dedication rule, one of the exceptions to the applicability of the doctrine of equivalents in US patent law.  

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