Which test to use for an intermediate generalization?

EPO Case Law

In T 0422/23, a decision by the Opposition Division (OD) on the allowability of a claim amendment was evaluated by the Board of Appeal (the Board). The amended claim concerned auxiliary request 2 (AR-2) that was upheld in opposition.

The invention concerned an electronic cigarette comprising an intelligent controller. The intelligent controller was there to monitor the status of the heating wire of the electronic cigarette, so that in case of malfunction the user could be informed on the reason of the malfunction.

In AR-2, the feature that the intelligent controller comprised a battery was left out of the claim, whilst it was present in claim 1 of the grandparent application as filed. The OD applied the three-point essentiality test to conclude that this intermediate generalisation was an allowable intermediate generalisation. The Board reviewed this decision as follows.

Background

The three-point essentiality test (EPO Guidelines H-V, 3.1) assesses if a replacement or removal of a feature is allowable according to Art. 123(2) EPC. The test may also be used to establish if subject-matter does not extend beyond the content of the earlier application as filed (Art. 76(1) EPC). For a positive assessment, all three criteria need to be met. The essentiality test is subordinate to the “gold standard” of G2/10 (reason 4.3). The criteria of the essentiality test are:

(i) the replaced or removed feature was not explained as essential in the originally filed disclosure;

(ii) the skilled person would directly and unambiguously recognise that the feature is not, as such, indispensable for the function of the invention in the light of the technical problem the invention serves to solve (in this context special care needs to be taken in cases where the technical problem is reformulated during the proceedings, see H-V, 2.4 and G-VII, 11); and

(iii) the skilled person would recognise that the replacement or removal requires no modification of one or more features to compensate for the change (it does not in itself alter the invention).

The Appeal

Two Appellants (A’s) questioned the assessment of the OD and pointed to claim 1 of the grandparent application, embodiments in the description of that application and the functional relationship between the battery and other features of the intelligent controller as presented in the grandparent application to dispute the decision of the OD.

The Respondent-Proprietor (R) pointed to a paragraph on the object of the invention [0005], a paragraph on the advantages of the invention [0007], and to method claim 10 to explain that a battery is not essential, as these disclosures do not mention a battery.

The Board took these considerations into account and started with stating that since the essentiality test is subordinate to the “gold standard”, principally the Board will (only) use the “gold standard”. The Board then pointed to the Decision of the OD, which stated:

"Also when applying the "gold standard" of G2/10, it is evident to the person skilled in the art from the discussion above [of the three point test] that the language of original independent claim 1 of the grandparent application that relates to the battery and the battery's connections with the other elements of the intelligent controller is not functionally or linguistically associated with the remaining features of independent claim I as originally filed and can therefore be omitted without violating the requirement of Article 100(c) EPC.”

The Board fully disagreed and pointed to that in claim 1 of the grandparent application, the battery feature was part of the claim, so was linguistically connected. Moreover, in this claim 1 the battery was explicitly defined to be connected to other features of the intelligent controller (such as the switch module, the voltage acquisition module, the control module and the display module) and even was defined to supply working voltage power to these features, which was without doubt its function.

Furthermore, the Board found that paragraph [0005] on the object of the invention did not shed light on whether the intelligent controller was disclosed without a battery, and that paragraph [0007] that stated advantages of the invention were directly related to the intelligent controller of paragraph [0006] (which comprises a battery). At last, method claim 10 did not disclose the structure of the intelligent controller, so was not suitable for assessing this structure.

Decision of the Board

Auxiliary request 2 was deemed not to meet Art. 76(1) EPC. R filed further requests, but in the end the decision of the OD was set aside, and the patent was revoked.

Summary written by the NLO EPO Case Law Team