An International Guide to
Patent Case Management for Judges

12.5.2 Patent infringement disputes

Patent owners considering legal action to defend their rights must first clearly identify which of their claims may have been infringed. An error sometimes committed in this regard is losing sight of what the plaintiff’s patent actually protects and what rights it actually confers. A strategy to avoid is focusing on the properties of the object, product or substance the plaintiff is commercializing, as it should not be assumed that they all correspond to the features of the invention as registered. It is important to bear in mind that in patent litigation, the latter and not the former is what matters. what needs to be perfectly clear in the complaint is what the plaintiff has registered specifically and how it has been unduly affected by the activities of a third party. Cases are lost when this basic point is forgotten.

A second important point in filing these complaints is to identify the features of what the defendant has been manufacturing or commercializing. This is precisely what should be compared with what is claimed in the patent. What the defendant may have subsequently registered is not relevant in this context, as infringement disputes are not about comparing titles according to legal priority. What matters is to verify whether the actions of the defendant constitute an infringement of the priority right registered by the plaintiff.

The best approach to these disputes is to accompany the complaint with an expert opinion⁵⁴ on related technical issues, with which the judge – however specialized the court may be in the subject matter concerned – may well be unfamiliar.⁵⁵ The opinion should focus first on the scope of the claims allegedly infringed, and then on how the defendant’s activities infringed them.

To clearly assess whether the conduct of the defendant constitutes an infringement of the plaintiff’s patent, the protected subject matter of the patent must be determined according to the patent’s definition of the exclusive right.⁵⁶ This means delving into a legal analysis that must be based on properly structured technical information. The plaintiff’s legal position will not otherwise be sufficiently robust.

Precise specification of what constitutes the patent’s subject matter will be of fundamental importance in deciding whether infringement has occurred. It must be remembered here that protected subject matter is defined by a patent’s claims as informed by the description and drawings accompanying them. In bringing action against an infringement, the first step is to determine the scope of patent protection.⁵⁷ This is because, as stressed by the Spanish Supreme Court, patent claims perform two functions. First, they define the subject matter to be protected by indicating the technical features of the invention necessary to execute the procedure or define the product concerned and thereby solve the technical problem identified in the specifications. And second, they determine the extent of protection conferred by the patent or patent application, taking into account the accompanying description and drawings.

The subject matter of the invention must be determined based on an analysis of the technical features in the characterization section, which must relate to the content of the preamble that introduces and contextualizes the invention. That permits what is novel about the invention to be identified, and thus for the extent and limits of the patent protection to be outlined. But to delineate more precisely where that protection is relevant to the case, it must be determined where the patent is exclusive and interpret the claims infringed to ascertain their technical and legal meaning in the context of the case. It is important to maintain the right legal balance in performing this analysis. The interpretation of claims should be neither too exorbitant nor too literal. The key is to find the right balance between equitable protection for the applicant and a reasonable degree of certainty for third parties (as described in the Protocol on the Interpretation of Article 69 EPC). Spanish case law in this area⁵⁸ admits no need for a strictly literal interpretation, allowing for a more intuitive approach, to find the true meaning behind the content of a claim. In determining the scope of patent protection, Spanish rulings have also tended to admit and factor in arguments based on the history behind patent applications and grants, including disclaimers, limitations and other steps taken by applicants in their interactions with patent offices.