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Infringement by equivalence

It is one of the most challenging subjects in the field of patents – equivalence. Henri van Kalkeren, patent attorney at V.O., explains: ‘Recent decisions of judges therefore remain relevant to us. It is and remains a relatively grey area.’

What does the word ‘equivalence’ mean?
‘The most important part of a patent are the conclusions, known as the claims. These claims determine the scope of protection of the patent. Put simply, a competing product falls under the scope of protection of a patent if it fulfills all the elements in one of the claims.’

However, sometimes elements from the claim do not literally correspond with the (alleged) infringing product, but they come close – certainly if you look into the idea behind the invention. By looking at the literal claims alone, you are failing the patent holder according to the law, because this means that it becomes unreasonably simple for a producer to bypass a patent. On the other hand, according to the law, the meaning of the claim must also not be construed so widely that it is used merely as a guideline. This is where the grey area emerges.’

‘In order to strike the right balance, the equivalence doctrine has been introduced in legislation. As a result, the judge must determine whether an element from the product that is not literally the same as an element in the claim can be deemed an equivalent, as a result of which the product is still covered by the scope of protection.’

Can you clarify this with the help of an example?
‘The invention of the transistor is a great, classic example. Prior to the invention of transistors in 1950, electronic components were mainly based on vacuum tubes with anodes and electrodes. These components were therefore regularly described literally in patent applications.’

‘After transistors were introduced, vacuum tubes for the same electronic components were no longer necessary all of a sudden. By interpreting a patent literally, an infringing party would get away with this by merely replacing a vacuum tube with a transistor under a patent. However, at the time of their patent application, the patent holder could not have anticipated that their patent would become useless just by mentioning a vacuum tube in it. A literal interpretation therefore fails the patent holder. It does not reflect what the patent holder actually invented.’

Why is equivalence such a challenging term for inventors?
‘In my experience, inventors and engineers don’t like grey areas. And that’s precisely what equivalence relates to. It’s not always clear what falls under the claims, because you cannot always follow the literal wording of the claim. As a result, the scope of protection of the patent is constantly under discussion. The judge must make a decision in these cases.’

Why is this a topical issue right now?
‘In the Netherlands and various other European countries, there is a case in which the key question is whether an acid form of a cancer drug is covered by the scope of protection of a patent that literally calls it sodium salt, and not the acid form, in the claims. In England, the Supreme Court judged that this acid form should be deemed an equivalent to sodium salt. Undoubtedly, this judgment influences other jurisdictions.’

Any questions?
Please contact Henri van Kalkeren via T +31 20 520 79 92 or h.vankalkeren@vo.eu.

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