Unity of Invention

Statutory requirements

6.1 Section 25(5)(d) requires that the claims relate to one invention or group of inventions which are so linked as to form a single inventive concept.

6.2 Rule 25 further sets out that:

(1) where 2 or more inventions are claimed (whether in separate claims or as alternatives within a single claim), such inventions shall be treated as being so linked as to form a single inventive concept only where there is a technical relationship among those inventions involving one or more of the same or corresponding special technical features.

(2) In this rule, “special technical features” means those technical features which define a contribution which each of the claimed inventions, considered as a whole, makes over the prior art.

6.3 Whether or not a particular technical feature makes a “contribution” over the prior art, and therefore constitutes a “special technical feature”, is considered with respect to novelty and inventive step.

6.4 Unity is a ground for refusal under the Patents Act but is not a ground for revocation, and as a consequence there is no judicial or hearing guidance from Singapore on this issue. However, the wording of the Singapore law mirrors the wording of PCT Rules 13.1 and 13.2. Guidance for practice in Singapore is therefore taken from Chapter 10 of the PCT International Search and Preliminary Examination Guidelines (“The PCT Guidelines”)

6.5 There are several administrative considerations that underpin this requirement: the presence of multiple inventions in a granted patent make it more onerous for third parties undertaking searches of the prior art or seeking to determine their freedom to operate; there are additional costs in search and examination without additional fees to cover the cost; and a patent for several inventions could result in additional complexity in the system (for example multiple infringement/revocation actions in relation to the same patent on different matter and grounds).