The Doctrine of Equivalents: Examination of the Law in Denmark

In many jurisdictions, the scope of protection afforded by a patent is defined by the claims as read either literally or under doctrine of equivalents.  Infringement based on the doctrine of equivalents is generally not based on any statutory law but rather has been established via case law (e.g. Court decisions).  The purpose of the doctrine of equivalents is to promote fair patent coverage so that trivial departures (e.g., variants or deviations) from the claim language cannot be used to avoid infringement. 

This is the fourth post in our series examining the law governing the doctrine of equivalents in several European countries.  Our first post examined the law governing the doctrine of equivalents in Spain, our second post examined the law in the Netherlands, and our third post examined the law in Germany.  These posts can be viewed here:  Doctrine of Equivalents – Spain, Doctrine of Equivalents – the Netherlands, and Doctrine of Equivalents – Germany.

Doctrine of Equivalents in Denmark

Background

Despite its somewhat small size, Denmark is a fairly litigious country when it comes to patent litigation.  Some reasons for this are:  the cost of litigation is not extremely high and Denmark is a highly technically developed country with many specialized industries (such as, for example, pharmaceuticals).  In Denmark, courts are organized in a three-tier system comprising: (a) city courts; (b) two high courts (the Eastern and Western High Courts) and the Maritime and Commercial High Court; and (c) the Supreme Court.  Most patent proceedings, including proceedings for preliminary injunctions, are decided by the Maritime and Commercial High Court in Copenhagen (Maritime Court), as the court of first instance.  Appeals from the Maritime Court are to the Eastern High Court, and in some instances, the Supreme Court. 

As the main venue for patent cases, the Maritime Court can be considered to be a specialized patent court that having significant expertise in patent matters. Generally, cases before the Maritime Court are heard by a permanent law judge with a law degree and two technically qualified judges (who each may have a law degree) who are individuals with relevant commercial and/or technical backgrounds and/or experience.  The proceedings are generally conducted in Danish and infringement and validity claims are heard simultaneously (i.e., there is no bifurcation).  In addition to patent cases, the Maritime Court hears other commercial cases such as trademarks, designs, contracts, labor rights, bankruptcy, maritime law, etc., but no criminal cases.

Claim Construction

According to Article 69 European Patent Convention (EPC) the extent (“the scope”) of the protection conferred by a European patent or application is determined by the claims.  Nonetheless, the description (i.e., specification) and drawings are also considered when interpreting the claims.  Specifically, in Denmark, the claims are construed to determine the “essential” or “significant” features or parts of the invention.  Language in the claims that is not relevant to the “essential” or “significant” parts of the invention (e.g., namely, non-essential features) may be given less or very little weight when assessing the scope of protection. 

Statements made by the patentee during examination (i.e., prosecution) can be relevant to claim construction, particularly if made for purposes of avoiding prior art (e.g., novelty and/or inventive step).  Thus, as will be discussed in further detail herein, prosecution history estoppel may apply in Denmark both in the context of construing the claims as well as in the application of equivalency under the doctrine of equivalents.   

Patent Infringement

The protocol for interpreting Article 69 EPC, which is an integral part of the EPC according to Article 164(1) EPC, states:

Article 1 – General principles

Article 69 should not be interpreted as meaning that the extent of the protection conferred by a European patent is to be understood as that defined by the strict, literal meaning of the wording used in the claims, the description and drawings being employed only for the purpose of resolving an ambiguity found in the claims. Nor should it be taken to mean that the claims serve only as a guideline and that the actual protection conferred may extend to what, from a consideration of the description and drawings by a person skilled in the art, the patent proprietor has contemplated. On the contrary, it is to be interpreted as defining a position between these extremes, which combines a fair protection for the patent proprietor with a reasonable degree of legal certainty for third parties.

Article 2 – Equivalents

For the purpose of determining the extent of protection conferred by a European patent, due account shall be taken of any element which is equivalent to an element specified in the claims.

The protocol for interpreting Article 69 EPC is applicable to granted European patents validated in Denmark. However, according Article 64(3) EPC, the question of infringement of a European patent is dealt with under national, namely, Danish law.

Similar to Article 69 EPC, Section 39 of the Danish Patent Act (DPA) stipulates that:

The extent of the protection conferred by the patent and the patent application shall be determined by the patent claims. For the interpretation of the claims the description may serve as a guide.

Article 3 of the DPA defines what acts are not to be performed by third parties, i.e., what acts can potentially constitute infringement.  Specifically, according to this article:

…without permission of the patent owner, no one may exploit the invention by making, offering, putting on the market or using a product that is the subject matter of the patent, by importing or possessing a product for these purposes, by using a process that is the subject matter of the patent or by offering the process for use in Denmark, if the person offering the process knows or it is obvious in the circumstances that the use of the process is prohibited without the permission of the patent owner, or by offering, putting on the market or using a product obtained by a process that is the subject matter of the patent, or by importing or possessing the products for these purposes. 

There are two major types of patent infringement in Denmark: 1) literal infringement; and 2) infringement under the doctrine of equivalents. In order to assess whether infringement has occurred it is first necessary to interpret the terms used in the claims as discussed previously herein.  Once the meaning of the claims has been construed, a determination is made whether the claims have been literally infringed, before moving on to determine whether the claims have been infringed by equivalence.  Of course, an assessment of infringement under the doctrine of equivalents is only made when literal infringement has not been found.

Literal infringement

In Denmark, literal infringement requires an analysis of whether each and every essential or significant part of the invention can be found in the alleged infringing product or process.  If each and every essential or significant feature or part of the invention cannot be found in the alleged infringing product or process, namely, if deviations exist between the essential or significant features or parts of the invention and the alleged infringing product or process, then there can be no finding of literal infringement and the analysis moves to whether or not infringement exists under the doctrine of equivalents.

Infringement under the Doctrine of Equivalents and Prosecution History Estoppel

Under the doctrine of equivalents, if deviations exist between the essential or significant features or parts of the invention and the alleged infringing product or process, a determination must be made whether the deviations would be an obvious alternative recognized by one skilled in the art to be useful for the same purpose as the essential or significant feature or part recited in the claims. It is a fundamental premise that the protection afforded under the doctrine of equivalents reflect a balance between clarity and fairness. Specifically, the analysis involves determining whether the deviation (1) performs the same function in the same way as the essential or significant feature or part recited in the claim in order to solve the same problem as the claimed invention; (2) would be recognized by one skilled in the art as being an obvious alternative to the essential or significant feature or part recited in the claim; and (3) was not specifically excluded during examination (namely, the allegedly infringing product or process  must not belong to the prior art). 

As mentioned above, one limitation on equivalency in Denmark is the doctrine of prosecution history estoppel.  Generally, the Maritime Court will review statements and/or amendments made by the patentee during examination.  Statements made by the patentee to the effect that a certain embodiment is not covered by the scope of the claims will usually be binding.  Likewise, arguments and/or amendments made to claims to overcome novelty and/or inventive step rejections will preclude a finding of infringement under the doctrine of equivalents. 

The High Court decision U 2009/1523 (Guldager) set the direction for a more international approach toward applying Article 69 EPC which has been followed in several recent cases. An examples of a case in the life science area involving the doctrine of equivalents are:  Maritime Court decision A-19-17 (Eli Lilly and Company and Eli Lilly Danmark A/S v. Fresenius Kabi AB v/Fresenius Kabi and Fresenius Kabi Oncology Plc.), concerning Eli Lilly’s DK/EP 1 313 508 relating to the use of pemetrexed in combination with vitamin B12 and optionally, folic acid (covering the product Alimta®). 

This post was written by Lisa Mueller of Casimir Jones, and Lars Pallisgaard Olsen and Verena Simpson of Guardian IP Consulting.