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| James VI and I Artist Daniel Mytens the Elder Public Domain Source Wikimedia |
14 Dec 2025
Every patent since the Statute of Monopolies 1623 has been a bargain between the owner of an invention and the state. In consideration of disclosing how to make or use the invention, the state grants the owner a monopoly of the exploitation of the invention for up to 20 years. The two sides of the bargain are set out in the specification which s.14 (2) (b) of the Patents Act 1977 requires every patent application to contain. The specification must incude "a description of the invention, a claim or claims and any drawing referred to in the description or any claim. S.14 (3) requires the specification to "disclose the invention in a manner which is clear enough and complete enough for the invention to be performed by a person skilled in the art." Failure to "disclose the invention clearly enough and completely enough for it to be performed by a person skilled in the art" is a ground for revocation under s.72 (1) (c) of the Act.
Eli Lilly & Company v Human Genome Sciences Inc."i) the first step is to identify the invention and that is to be done by reading and construing the claims;
ii) in the case of a product claim that means making or otherwise obtaining the product;
iii) in the case of a process claim, it means working the process;
iv) sufficiency of the disclosure must be assessed on the basis of the specification as a whole including the description and the claims;
v) the disclosure is aimed at the skilled person who may use his common general knowledge to supplement the information contained in the specification;
vi) the specification must be sufficient to allow the invention to be performed over the whole scope of the claim;
vii) the specification must be sufficient to allow the invention to be so performed without undue burden."
Types of Insufficiency
In Zipher Ltd v Markem Systems Ltd and another [2009] FSR 1, [2008] EWHC 1379 (Pat), Mr Justice Floyd noted at para [362] that although insufficiency is a single objection to the validity of a patent, it may arise in several different ways. There is classical insufficiency where the express teaching of the patent does not enable the skilled addressee to perform the invention. The second type is Biogen insufficiency after Biogen Inc v. Medeva Plc (1997) 38 BMLR 149, [1996] UKHL 18, [1997] RPC1. Biogen insufficiency is concerned with the breadth of the claims. The teaching may be enough to bring the skilled reader within the scope of the claims, but it will also encompass products or processes that owe nothing to the teaching. The third type of insufficiency arises through ambiguity. If the skilled addressee cannot tell whether he or she is working the invention or not, the specification is insufficient. Mr Justice Floyd observed that in every case the purpose behind the objection is to prevent a patentee from laying claim to products or processes which the teaching of the patent does not enable in the relevant sense.
Further InformationCases applying those principles and relevant articles are listed below, and these will be updated from time to time. Call me on +44 (0)20 7404 5252 during office hours or send me a message through my contact page for more information.
