The impact of adding subject matter before the European Patent Office

By Suzanne Oliver, HLBBshaw Ltd

Introduction

It is a requirement under European Law that any amendment which is made to a patent or patent application should not add subject matter that extends beyond the content of the application as filed. The underlying idea of the restriction is that an applicant is not allowed to improve his position by adding subject-matter not disclosed in the application as filed, which would give him an unwarranted advantage and could be damaging to the legal security of third parties relying on the content of the original application.

Contravening this requirement is not only a ground of rejection of an application before the European Patent Office (EPO), but may also be a ground for revocation of a granted patent at European national offices. This means that any amendment made pre-grant (even if approved by the examining patent offices themselves) could create a potential weakness in the granted patent, which may then be exploited by a third party during opposition proceedings, or later when the patent is enforced nationally.

The law regarding added subject matter is implemented very strictly by the EPO (as well as relevant national offices) and the consequences of falling foul of it can be disastrous. Therefore this article aims to provide a practical review of this area of law, as well as the relevant European case law.

European Law and Practice

Article 123(2) of the European Patent Convention (EPC) concerns the addition of subject matter both pre-grant and post-grant and reads as follows:

�The European patent application or European patent may not be amended in such a way that it contains subject-matter which extends beyond the content of the application as filed� (see text box).

Article 123(3) EPC concerns the impact of the addition of subject matter post grant (ie during opposition proceedings) and reads:

�The European patent may not be amended in such a way as to extend the protection it confers.�

The Application as Filed
With regards to Article 123(2) care should be taken in assessing what was in �the application as filed�, as it refers to the addition of matter to the original application, i.e. to the whole of the description, any drawings and any claims present at filing, then if the drawings filed initially were informal ones, it is these, not the subsequently filed formal drawings, which must be used for judging the content of the application “as originally filed”. Further, it seems that a priority document also does not form part of an “application” and also that, while a priority document has evidentiary effect, it cannot be taken into account in establishing the content of the application as filed, even if filed at the same time as the European application (see EPO Decision T 260/85, AMP/Coaxial connector, and see also EPO Examination Guidelines C-VI, 5.4). The EPO has also decided that the abstract cannot be used to interpret the content of the application for Article 123(2) EPC purposes (see EPO Decision T 246/86).

Adding subject matter by amendment (addition, alteration or deletion)

The addition of subject matter is the case most easily explained. For example, in an application which describes and claims apparatus having a �resilient biased means�, without disclosing any particular kind of resilient means, an objection would usually be raised if an amendment is made to the application to state that the means are �helical springs�. If, however, it could be demonstrated that the drawings (as interpreted by the skilled person) show helical springs, then this amendment would be allowable.

However, cases usually harder to grasp normally relate to more �subtle� ways that matter can be added, such as by deletion, by �intermediate generalization� or by selection from a range.

Deletion

Deletion of any term in a European Patent application should be done with great care, particularly if it was originally made clear that the feature deleted was essential to the claimed invention. In European practice, the actual deletion of material is usually the very last resort, use instead is made of other means of severance, such as �disclaimers� (see text box headed �Disclaimers�).

However, EPO Examination Guidelines state¹ that the replacement or removal of a feature from a claim does not violate Article 123(2) EPC �if the skilled person would directly and unambiguously recognise that:

(i) the feature was not explained as essential in the disclosure;

(ii) 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; and

(iii) the replacement or removal requires no real modification of other features to compensate for the change.�

Intermediate generalizations

�Intermediate generalizations� are best explained by way of example. If in a patent application claim 1 originally disclosed features A, B and C and dependent claim 2 originally disclosed features D, E, F, then an amendment that results a main claim having features A, B, C & E would not be permissible, unless that combination of features has already been elsewhere disclosed in the application as filed. Otherwise the only permissible amendment is one that results in a claim to features A, B, C, D, E & F.

Furthermore, if an invention is claimed in a broad claim and one particular embodiment is shown in a drawing, the drawing may show a particular implementation having many features, not all of which are essential to the invention as claimed in the originally filed broadest claim. The broad wording of the claim was, of course, present on filing, so cannot add subject matter. However, if during prosecution, it is desired to add one or more features that are shown in the drawing, but not all the features of that implementation then the amended claim is an intermediate generalisation between the original claim 1 and the implementation shown in the drawing. That amended claim is considered to add subject matter because, although the particular features that have been added to claim 1 are present in the drawing, the drawing only shows them in combination with all the others and there is no disclosure in the specification of the particular combination of features now being claimed. This example assumes, of course that the intermediate implementation is not specifically described in the specification. Nevertheless, a description of the particular implementation, without clearly stating that particular features thereof can be “split off” from the remaining features would not change the above conclusion.

Selection from a range

Generally, in Europe it is possible to extract numerical figures from the examples of the description and then use these as support for a range embraced by those values. However, it is possible to introduce a parameter from a prior art document if this acts as a disclaimer to distinguish the invention over that prior art².

For example, in one patent there was disclosed a general range of 30% to 60% and a preferred range of 35% to 50%. The patentee wished to make an amendment of the general range to read �30% to 50%�. The EPO decided³ that in such a case a range which combined an expressly disclosed preferred range (35% to 50%) and a �part range� between one of the limits of the preferred range (35%) and the nearest limit of the general range (30%) was �directly and unambiguously derivable� from the unamended patent. Thus, the range could be amended to read �30% to 50%� without contravention of Article 123(2) EPC. An amendment to read �30% to 45%� would not have been allowable.

It should be noted that the rules regarding the addition of subject matter also apply to the introduction of statements of new (i.e. previously not mentioned) effects of the invention such as new technical advantages, or a revision of stated technical problem. They also apply to any amendments made to description, drawings or claims made during the International phase of a Paris Convention Treaty (PCT) application, prior to entering the European regional phase.

Further, an amendment solely to the dependencies of a claim, the result of which gives rise to a new combination of features not previously disclosed may also be deemed to add subject matter. This situation arises most often when large numbers of claims are reduced after the international phase of a PCT application in order to avoid heavy excess fee liabilities. Removing great swathes of duplicated claims having no care for any new combinations of claims left behind may lead to accidental introduction of subject matter without any specific language actually being altered. For example, if in a patent application claim 2 depends on claim 1 only and claim 3 depends on claim 1 only and an amendment is made to alter claim 3 to depend on both claims 1 and 2, then unless this combination of features is disclosed in the application as filed, it would not be allowed.

The impact of an amendment which is deemed to add subject matter

As mentioned previously, the addition subject matter (by addition, alteration or deletion) may be a ground for invalidity, whether or not a prosecution Examiner accepts the application, both for opposition purposes and at any time after grant. Furthermore, Article 123(3) EPC prohibits a granted patent being amended in such a way as to extend the protection conferred by the patent (this is in contrast to the position pre-grant when this limitation does not apply).

Thus, even if the Examiner accepts an amendment to an application during prosecution, the possibility is always there that this ground can be raised in the future. Thus, as far as the claims are concerned, this may be something that cannot be dealt with by amendment after grant (including at opposition) because claims cannot be broadened, for example by deletion of subject matter that was found to be added during prosecution.

For example, in such a situation where an amendment that added subject matter was made to a claim during prosecution, the claim cannot later (during opposition or subsequently) be amended to excise that added subject matter because this would broaden the scope of the granted claim, even if this simply brings the claim back to what was there prior to the amendment during prosecution. Thus, such an amendment becomes effectively incurable.

On the other hand, if the added feature, does not provide a technical contribution to the subject-matter of the claimed invention, and merely limits the protection conferred by the patent as granted by excluding protection for part of the subject-matter of the claimed invention as covered by the application as filed, this feature may be maintained⁴.

Disclaimers
The EPO have decided (in decisions G 1/03 and G 2/03) that limiting the scope of a claim by using a “disclaimer” to exclude a technical feature not disclosed in the application as filed does not infringe Article 123(2) EPC in the following cases:

(i) restoring novelty over a disclosure under Art. 54(3);

(ii) restoring novelty over an accidental anticipation under Art. 54(2).

(iii) removing subject-matter which, under Art. 52 to Art. 57, is excluded from patentability for non-technical reasons. For example, the insertion of “non-human” in order to satisfy the requirements of Art. 53(a) is allowable.

However, an undisclosed disclaimer is not allowable if:

(i) it is made in order to exclude non-working embodiments or remedy insufficient disclosure;

(ii) it makes a technical contribution.

An undisclosed disclaimer is, in particular, not allowable in the following situations:

(i) the limitation is relevant for assessing inventive step;

(ii) the disclaimer, which would otherwise be allowable on the basis of a conflicting application alone (Art. 54(3)), renders the invention novel or inventive over a separate prior art document under Art. 54(2), which is a non accidental anticipation of the claimed invention;

(iii) the disclaimer based on a conflicting application removes also a deficiency under Art. 83.

This �squeeze� between a patent claim which contains an unlawful amendment made in prosecution and the fact that its rectification contravenes Article 123(3) EPC is not uncommon and usually fatal in opposition proceedings.

As previously mentioned, in most national offices that examine, such as in the United Kingdom (UK) it is also a ground for revocation of a granted patent if matter has been added during prosecution. The law in most European national states party to the EPC has in most cases been harmonized and therefore take an equally strict view of the application of Articles 123(2) and (3) EPC. Specifically in the UK, the relevant laws are supposed �to have, as nearly as practicable, the same effects in the United Kingdom as the corresponding provisions of the European Patent Convention�⁵.

So what is allowed?

Anything which can �directly and unambiguously be derived from the application as filed, such as an �obvious� correction or an amendment which has direct basis (ie can be supported by a page and line number reference of the exact specific text). Also, the importation of all the features of a sub claim into a main claim is allowable, as well as an indication as to specific embodiments �not being of the present invention� (as require by EPO examiner�s during grant procedures) and also disclaimers (see text box headed �Disclaimers�).

How do I decide whether an amendment adds matter?

In most cases the assessment of whether subject matter has been added to an application is not clear cut. However, it has been said that the assessment of added subject-matter corresponds to the EPO�s assessment of novelty. Although it should be noted that the EPO have stated⁶ this is only �in so far as both require assessment of whether information is directly and unambiguously derivable from that previously presented, in the originally-filed application or in a prior document respectively�. Therefore it should be stressed that the applicability of a “novelty test” in relation to added subject matter, always depends upon the circumstances.

Conclusions and Final Note

It should now be apparent that great care should be taken when amending a patent application during European prosecution and advice from a European Patent Attorney should also be taken where necessary.

Furthermore the �squeeze� effect of Article 123(2) and (3) EPC has been the subject of great debate within the Europe Patent System and various proposals have in the past been put forward for overcoming it by an amendment of the EPC, possibly by adopting a “footnote” solution which would allow the amendment previously made to stand but with a note that “no rights or benefit shall be derived from [such amendment]”, but as yet none of these proposals has found general approval.

Suzanne Oliver (suzanne.oliver@hlbbshaw.com) is a member of the HLBBshaw Electronics, Telecoms & Computer Science Group. She has a Masters degree in Electronic Systems Engineering and has Postgraduate industrial experience with satellite network and telecommunications companies in the UK and USA. Suzanne is a Member of the IET and a Chartered Engineer.

At C VI 5.3.10 [↩]
See EPO Decision T 982/94 [↩]
See EPO decision T925/98 [↩]
See EPO decision G 1/93 [↩]
See sections 72(1), 72(2) and 130(7) of the 2004 UK Patents Act [↩]
See EPO Decision T 194/84, GENERAL MOTORS/Cellulosic fibres [↩]

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The impact of adding subject matter before the European Patent Office