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2019 Sir Hugh Laddie Lecture: No cats and no doctrine of equivalence?

July 9, 2019

The 2019 Sir Hugh Laddie Lecture at the UCL Laws Institute of Brand and Innovation Law took place on 13 June.  The guest speaker at this annual event in honour of IBIL's founder was Willem Hoyng, Professor of Intellectual Property Law at the University of Tilburg, who has had a distinguished career in intellectual property law.  Sir Robin Jacob, co-director of IBIL, was in the chair.  I attended the lecture with freelance colleague Dean Evans.

Discussion of the "doctrine of equivalence (or equivalents)" concerns the position taken by courts, when deciding on infringement of a patent, on a spectrum extending from strict literal interpretation of the wording of the patent claims (the operative part of the patent text) on the one hand, to consideration of whether the alleged infringing device or process is "equivalent" to the one claimed in the patent, on the other hand.  Different jurisdictions take differing views on this matter, and this was the point of departure of Professor Hoyng's talk, which began with a history of early developments in the international patent system which shaped the literal <> equivalent dichotomy.


In England, the Statute of Monopolies in 1623 sought to remove the Sovereign's power to grant monopolies for income-generating purposes and ensure that a monopoly was granted only if really deserved.  This established the importance of the letter of the contract, providing the background against which the literal approach to patent claim interpretation and fairly narrow scope of protection developed.  In France the first Patent Act in 1791, shortly after the Revolution, was based on the idea that each human being is the owner of his/her innovation "Toute nouvelle découverte est la propriété de son auteur".  This emphasis on the idea of the invention, rather than the textual expression of it, led to a rather broad scope of protection. 


In the Netherlands, Germany and Switzerland in the nineteenth century there was a movement against patents. Bismarck advocated abolition of patent protection.  The Netherlands and Switzerland did abolish patents, but after seeing the progress made by the US, they reinstated a patent system to promote economic activity.  It was realised that for this to work, the system had to be liberal and not too literal.  In the Netherlands the "inventive idea behind the claim" took precedence.


The two competing views on interpretation continued in play through the discussions for the Strasbourg Patent Convention in 1963 (the "terms" of the claims versus the "content").  The UK denied the existence of the doctrine of equivalents.  After the 1960s the "European" camp moved progressively towards a more literal interpretation.  UK judges had been keen on equivalents but the UK government had not, so the effect was that "the UK stayed where they were, Europe moved".


Via a detour in which he criticised the European Patent Office for being too keen to grant patents and lowering the standard of inventive step, leading to a high percentage of invalid patents, ("granting small inventions with small scope should not lead to giving small scope to big inventions"), Professor Hoyng returned to the doctrine of equivalents, which in his opinion is not a good way of interpreting claims.  There are too many competing views and varying questions to be asked in the process of deciding equivalence.  It can lead to genuine invention not being rewarded.  The "inventive idea behind the wording of the claim" should be protected to encourage innovation, and applicants should not be penalised for mistakes in drafting of the claims.  Nit-picking is not good for the system.


Metaphorical cats made a cameo appearance, while inspection of the patent prosecution history "file wrapper estoppel" was mentioned, Professor Hoyng (I think) concurring with Sir Robin Jacob that "the expense and difficulty [of referring to it] far outweigh the benefits".


Errors, omissions, misunderstandings etc. are mine.


The video of this lecture is available here.


Photo: Priory Translations A Hargreaves








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