Wednesday, 28 July 2010

T 765/07 – What Is Essential?

The case law has elaborated the so-called “essentiality test”, also referred to as “is it essential?” test, for evaluating whether the deletion of a feature from a claim is allowable in view of A 123(2). According to T 331/87, the replacement or removal of a feature from a claim may not be in breach of A 123(2) if the skilled person would directly and unambiguously recognise that (1) the feature was not explained as essential in the disclosure, (2) it was not, as such, indispensable for the function of the invention in the light of the technical problem it served to solve, and (3) the replacement or removal required no real modification of other features to compensate for the change.

[1.1] In accordance with A 76(1), “[a European divisional application] may be filed only in respect of subject-matter which does not extend beyond the content of the earlier application as filed”. In the present case the earlier application is the parent application […]. The established criterion, analogous to A 123(2), is that the subject-matter of a divisional application must be directly and unambiguously derivable from the parent application. This is the criterion adopted by the board in the present case.

[1.2] In the view of the board, the feature of claim 1 of the main request “wherein the spreading code generated by the spreading code generator is supplied to the delay circuit (319, 319’)” is not directly and unambiguously derivable from the parent application as filed. In accordance with this wording, the delay circuit could be placed anywhere on the output side of the generator, i.e. anywhere between the generator and antenna.

The appellant argues that the claim wording is supported by claims 19 and 21 as well as the passage at column 9, lines 6-10 of the published parent application. However, in all these passages it is explicitly mentioned that the signal from the delay circuit 319 is output to the multiplier/modulator 320 (see also Fig. 3), without there being any suggestion that an alternative position of the delay might be contemplated. Hence, claim 1 includes matter not directly and unambiguously disclosed in parent application as filed, contrary to A 76(1).

[1.3] In the oral proceedings the appellant argued that the skilled person would recognise that the location of the delay circuit between the code generator and the modulator was not an essential aspect of the invention and hence could be omitted from the claim in accordance with the “essentiality test” used in decision T 331/87

 In the letter of reply to the summons to oral proceedings, it was also apparently argued (albeit in respect of a different claim wording), with reference inter alia to decision T 1067/97, that the delay circuit and the modulator/multiplier 320 have no close functional or structural relationship, and that therefore it was allowable that the modulator/multiplier 320 be omitted from claim 1.

[1.4] However, as indicated above, the board considers that the correct criterion to apply is whether or not the claimed matter is directly and unambiguously derivable from the parent application as filed. As stated above, there is no basis in the parent application for any other position of the delay circuit.

Moreover, with regard to the appellant’s arguments, the board is not convinced that the location of the delay circuit between the code generator and the modulator should not be regarded as “essential”, as other locations of the delay circuit would have plausibly undesirable consequences such as adding delay to the data signal input to the modulator. Hence, the “essentiality test” is not applicable in the present case.

Furthermore, in the board’s view the case law exemplified by T 1067/97 does not apply to the present application since the code generator, the delay circuit, and the modulator clearly interact closely to provide a spread spectrum signal with the correct phase. They therefore have a close functional and structural relationship. Hence, the board finds the appellant’s arguments unconvincing.

[1.5] The board therefore concludes that claim 1 of the main request does not comply with A 76(1).

This case deals with rather complex subject-matter and it may well be that the Board was right in rejecting the deletion of the feature under consideration. However, I am not convinced that the argument used by the Board is satisfying. If I understand the Board correctly, it says that the feature should be considered as essential because its deletion would have undesirable consequences. I am not sure that this is what essentiality is about. I would think that a feature is essential if it is necessary for the solution of the objective technical problem. If the problem is still solved after deletion of the feature, even if other drawbacks appear, I would believe the feature not to be essential. Perhaps the Board considered condition (3) of T 331/87 and thought that the replacement or removal required a real modification of other features to compensate for the change in order to get rid of the above mentioned undesirable consequences? If so, I think the Board went beyond what T 331/87 had in mind: condition (3) stems from T 260/85 where the compensation clearly is related to solving the objective technical problem.

If you wish to read the whole decision, you may click here

NB: To read another post dedicated to the essentiality test, just click here

p.s.: I will be abroad for some time, without any certainty concerning Internet access. Therefore, I have to activate comment moderation. Sorry for the inconvenience.


pat-agoni-a said...

In G 2/98, Requirement for claiming priority for the "same invention", the EBA analyzed whether the distinction made in T 73/88 between technical features
which are related to the function and
effect of the invention and technical
features which are not made sense (point 8.3).
It said: "This approach is problematic because there are no suitable and clear, objective criteria for making such a distinction; it could thus give rise to arbitrariness. In fact, the features of a claim defining the invention in the form A+B+C do not represent a mere aggregation, but are normally inherently connected with each other. Therefore, if the above-mentioned distinction is to be made, the answer to the question whether the claimed invention remains the same, if one of these features is modified or deleted, or if a further feature D is added, depends very much on the actual asessment of the facts and circumstances of the case by each individual deciding body. Different deciding bodies may thus arrive at different results when assessing these facts and circumstances. Furthermore, as pointed out in the referral of the President of the EPO (cf. point III.(v) supra), it has to be borne in mind that the assessment by these different deciding bodies of whether or not certain technical features are related to the function and effect of the claimed invention may completely change in the course of proceedings. This is the case, in
particular, if new prior art is to be
considered, with the possible consequence that the validity of a hitherto acknowledged right of priority could be put in jeopardy. Such dependence would, however, be at variance with the requirement of legal certainty."
Although it may be argued that the "is it essential" test is not exactly the same as the test "features which are related to the function and effect of the invention" it seems very similar. Also the requirements for claiming priority have some similarity with the requirements for a divisional application, ie the applicant should not gain an advantage over the prior art at the priority or the filing date, respectively.
The EBA found that claiming priority for the "same invention" amounted to require that the skilled person could derive directly and unambiguously the subject-matter of the claims from the priority document. No reference, not even remote, was made on "essential" features. In particular, since as mentioned above, what is essential may change in the course of the proceedings, eg when the problem has to be reformulated.

Oliver said...

You are certainly right in saying that what is essential can change when new prior art appears. Do you draw the conclusion that the essentiality test should be abandoned? It sure is more laid-back than some of the recent A 123(2) decisions.

Anonymous said...

Regarging item (2) in the essentiality test:

Is there any case law that supports the view that the objective problem (the problem solved in light of the closest prior art) should be considered when determining if a claim feature is essential?

In my understanding the "technical problem" in question must be the a priori problem rather than the objective problem. Hence what is essential does not depend on prior art. What is essential is merely based on the content of the application.

Please correct me if I am wrong.

Oliver said...

Wrong or right, there ain't no such thing in case law ;-).

Yours is an interesting question. If you have a look at the Case Law Book, you will see that T 784/97 shared your opinion, whereas T 583/93 admitted that features could become essential when new prior art had to be taken into account. I have not got the time to look for more recent case law; I have to catch my train.

To be sure, the problem of reformulation of the technical problem raises interesting questions from the A 123(2) point of view.

Also, in principle the set of essential features can only increase during the proceedings. But perhaps there may be exceptions even to this rule?

Anonymous said...

Decision T 910/03 seems relevant to this discussion, see in particular point 3.4 which appears to agree with pat-agoni-a's comment, and point 3.5 which explicitly rejects T 331/87.

I'm not sure I can agree with the reasoning in T 910/03. I believe the reasoning cited from G 2/98 (point 8.3) was not meant to explain the test "is it directly and unambiguously derivable", but was only meant to show why the test for A.87(1) cannot be less strict than "is it directly and unambiguously derivable", in particular not in respect of technical features unrelated to the "function and effect of the invention". See G 2/98, point 9: "From the analysis under point 8 supra," it follows that the test for A.87(1) is "is it directly and unambigiously derivable". So point 8.3 has absolutely nothing to do with the question under what conditions something is implicitly disclosed. Point 8.3 is therefore irrelevant for the question under what conditions the removal or replacement of a feature from an embodiment is implicitly disclosed.

Anonymous said...

On the other hand, the test "is it directly and unambiguously derivable using common general knowledge" makes it clear that Art. 54(2) documents that do not belong to the common general knowledge cannot have any influence on what is disclosed by the application as filed, and can therefore not be relevant for the question whether the removal or replacement of a feature from an embodiment or claim is allowable under Art. 123(2).

I find nothing objectionable in point 4.5 of T 583/93, though. It only states "Therefore, it is possible that features described as optional at the priority date later do become essential in the sense that they are necessary to delimit the invention from the prior art." Those features remain optional in the sense of Art. 123(2), but their inclusion become mandatory for complying with Art. 54/56.

The term "essential" is used in the case law in many different meanings.