2.11.8 Claims Relate to One Invention Only - Lack of Unity

Date Published

The considerations under sec 40(4) as to whether there is more than one invention claimed are the same as for lack of unity under Rule 13 of the PCT Regulations. Examiners are therefore to have regard to the following references, which contain a comprehensive guidance on assessing unity of invention:

Lack of unity may be directly evident “a priori”, that is, before considering the claims in relation to any prior art.  Alternatively, lack of unity may only become apparent “a posteriori”, that is, after taking (at least some) prior art into consideration.

In considering the prior art for lack of unity a posteriori, examiners are not to take account of subject matter disclosed in any E or P category document.

In assessing whether there is more than one invention claimed, consideration needs to be given to those features (“special technical features” in the PCT guidelines) of the claimed inventions which provide an advance over the prior art. Claims which involve the same “special technical features” will embody the same inventive concept and thus relate to the same invention. Where a claim does not avoid the prior art, its features cannot constitute “special technical features” for the purpose of assessing unity of invention between claims. Examiners should note that in this context "does not avoid the prior art" relates to novelty and inventive step.

Where the claims are considered not to involve the same "special technical feature", and thus are clearly not so linked as to form a single inventive concept, an objection is warranted.  

Lack of unity objections should be based on sound reasoning. Care should be taken in not raising objections based on a narrow, literal or academic approach [PCT/GL/ISPE/1 at paragraph 10.04].

Lack of unity is not to be determined with regard to the effort required to examine multiple inventions.  If the claimed inventions clearly are not so linked as to form a single inventive concept, then a lack of unity objection is warranted regardless of the ease of examining the second or subsequent inventions.  The degree of additional effort that would be required to examine multiple inventions is only a determinant in whether examiners are to examine the second or subsequent inventions.

A useful starting point for determining lack of unity is to firstly consider what the problem is that the application addresses (see Determining Lack of Unity).

For lack of unity considerations with regard to examination approach and the level of detail required in a report, see: