JUrISdIctIOn repOrt: denmArK
pAtent LItIGAtIOn—
tHe dOctrIne OF eQUIVALence
Annelise Holme
Home Patent A/S
The extent of protection of a patent determines the outcome of
“[...] tWO deVIceS Are eQUIVALent IF It cAn
infringements proceedings and thereby the actual value of the patent.
be SHOWn tHAt A deVIce AccUSed OF
Pursuant to § 39 of the Danish Patent Act, the extent of protection conferred
InFrInGementS perFOrmS SUbStAntIALLY
by a patent is determined by the claims, and therefore determination of a
patent infringement entails two steps:
tHe SAme FUnctIOn In SUbStAntIALLY tHe
SAme WAY tO ObtAIn tHe SAme reSULt AS
• The claims must be construed, and
deFIned In tHe pAtent.”
• The properly construed claims must be compared to the allegedly
infringing device.
This involves ascertaining the true meaning and scope of each claim
in light of the intrinsic evidence of record. This means the patent
specification, other claims in the patent and other relevant prior art, as a
short reasons for their decisions, and these decisions are usually rather
person skilled in the art would understand them. If necessary, the court
limited to the fact of the case in question, the Danish courts have never
may look to extrinsic evidence, such as the interpretation those skilled in
actually used the word ‘equivalent’, even though equivalence has been
the art would give to a claim, as well as dictionaries and technical papers
argued by the lawyers. The Danish courts have instead used the phrase
and articles.
‘the core of the patent’, which gives a broader scope of protection than the
In the context of patent litigation, claim construction is a question of law
strict literal meaning, but only if said scope can be understood by reading
and, in order to ensure a uniform interpretation of a European patent, the
the patent.
EPC 2000—which came into effect on December 13, 2007—included an
However, on March 27, 2009, the Danish Supreme Court used the term
amended Protocol on the interpretation of Article 69 EPC. This is intended
‘technical equivalence’ for the first time in a patent infringement case.
to bring about uniformity at a national level between contracting states to
the EPC when interpreting claims. In said case, the company Guldager A/S, which had obtained a European
patent validated in Denmark, sued the company Dansk Elektrolyse A/S
The amended text reads:
for patent infringement.
“For the purpose of determining the extent of protection conferred by a
The patent, which related to a method for corrosion-proofing a water
European patent, due account shall be taken of any element which is an
system, had a main claim that referred to a single water tank and the use
equivalent to an element specified in the claims.”
of electrodes directly connected to an electrolysis power source.
However, no definition of what is meant by “an equivalent” was included
Even though the infringing system had two water tanks and the system did
in the Protocol, and it is expected that this lack of a binding definition
not comprise electrodes that were directly connected to a power source,
will do little to achieve the desired uniform interpretation. The different
the Supreme Court stated “….that the used system falls within the scope
EPC countries will have different understandings of the term ‘equivalent’,
of protection or is at least considered to be technical equivalent with the
as this term is not based on a clear statute but on a large literature of
claimed invention”. The Danish Supreme Court awarded the proprietor
national decisions.
Guldager A/S DKr1.8 million ($340,000) in damages.
However, generally speaking, two devices are equivalent if it can be
This landmark decision is hopefully the beginning of a new era in which
shown that a device accused of infringements performs substantially the
the Danish courts will use the doctrine of equivalence in future decisions
same function in substantially the same way to obtain the same result as
in order to fully harmonise with the patent laws in Europe.
defined in the patent.
Based on the published patent decisions, it is clear that the Danish courts
are awarding patent protection beyond the strict literal meaning of the Annelise Holme is a partner at Holme Patent A/S. She can be contacted
wording of the claims. However, since the Danish courts usually give at: ah@holmepatent.dk
www.worldipreview.com World Intellectual property review September/October 2009 59
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