1. Introduction

In all patent systems, the concept of clarity, with particular regard to the claims, is implemented in the patentability requirements, because it is in direct connection to the overriding purpose of legal certainty.

However,  clarity cannot be easily identifiable in a single requirement; rather, it is scattered in a number of “clarity related requirements” that differ in many aspects and may well appear to define a nebula of possible deficiencies for a patent.

One trait common to the clarity related deficiencies is that they are scarcely dependent on the prior art and do not need an amendment in order to occur; indeed, clarity related requirements typically may be evaluated at the time of drafting the patent application. This is true for all Patent Offices.

Instead, the question as to whether clarity related requirements constitute a ground for invalidating a granted patent, either before a Court of the Patent Office, may well have different answers for different territories.

2. Different jurisdictions

Regarding this question, we focus here on three patent systems corresponding to the following territories: Europe, USA and Japan.

2.1 Europe

Regarding the administrative means for invalidating a patent before the EPO, i.e. opposition, the EPC excludes clarity from the grounds of opposition, wherein “clarity” includes all requirements falling under Art 84 EPC. This is ruled in Art. 100 EPC and has recently be confirmed by decision G3/14 of the Enlarged Board of Appeal of the EPO.

2.2 USA

The American Invent Act (AIA) established several means for challenging a granted patent at the administrative level, among which Post Grant Review (PGR) and Inter Partes Review (IPR) proceedings. As per PGR, patent “definiteness” under 35 U.S.C. § 112, is a ground for revocation. Instead, in IPR proceedings, a practitioner may not challenge a patent under definiteness as a ground, although the Board is not prohibited from invalidating that patent claims under § 112 in an IPR

Patent definiteness in the USA is also a ground for challenging a patent before the courts.

2.3. Japan

Japan recently re-introduced an administrative proceeding to oppose a patent before the Japanese Patent Office, following the amendment of the patent law dated 2014; such an Opposition is available since 1st April 2015. In this Opposition proceeding, patent clarity is a ground for challenging the patent.

Also, clarity is a ground for invalidating a patent before the courts.

3. A look into clarity related requirements

In order to investigate the role of patent clarity, its relevant requirements may be grouped in the following categories of deficiencies to be avoided in the patent claims.

a) Deficiencies that inhibit a precise identification of the boundaries of the scope of protection.

Category (a) may include for example vague terms and the use of functional features, or of features expressed in terms of the result to be achieved.

b) The content of the claim lacks support in the description

Category (b) typically comprises inconsistencies between the description and the claims, and situations where the number and nature of specific examples provided in the description do not adequately cover or address the range of technical solutions which fall in the broad definition provided by the claim.

c) The claim is incoherent with the technical achievement attributed to the claim

Category (c) essentially embraces the lack of essential features in a claim. The corresponding requirement evaluates the claim in relation to the technical effects which are linked to the claim features.

d) Minor deficiencies which may lead to wrong interpretations

Category (d) may include for example lack of antecedent basis and inconsistencies in the use of terms or numbers to indicate the various features.

4. Conclusion

Different Patent Offices and jurisdictions have dissimilar views about the role clarity must play, particularly in challenging the validity of granted patents; however, all of them seem to assign clarity a significant weight.

In this respect, the circumstance that a variety of heterogeneous requirements fall under the nebula of clarity may take some practitioners to underestimate clarity importance, both in patent drafting and in litigation.