Pages 145-157

WORKING SESSION

What amendments are permissible in order to be in line with the requirements under Article 123(2) and (3) EPC?

Klaus BACHER

Judge, Federal Court of Justice

What amendments are admissible under Article 123(2) and (3) EPC?

I. Introduction

I am not in the least unhappy about my slot as second speaker on this topic today for it provides me with the perfect opportunity to pick up where the previous speaker left off and, in particular, refer back to the principles that Mr Blumer explained so clearly.

The Federal Court of Justice has in the past – at least in my time there – received criticism (or praise) from several quarters for taking a different approach from that of the EPO boards of appeal on the application of Article 123(2) and (3) EPC. It may surprise you then to hear me advance the theory today that there are no fundamental differences between the Federal Court of Justice's decision-making practice and that of the boards of appeal. To help you decide whether my theory is valid, I propose to present a number of decisions of the Federal Court of Justice which turned on the content of the original disclosure or an extension of protection.

II. Procedures for amending a granted patent

Whether a patent's subject-matter extends beyond the content of the application as filed is something considered not only in grant proceedings. There are a number of different ways patent proprietors can amend the subject-matter of their patents, even after grant:

• They can defend their patent in an amended form in pending opposition proceedings, via either a main request or an auxiliary request. An amendment of this kind is generally valid in all contracting states.
• They can request limitation under Article 105a EPC in central proceedings at the European Patent Office. An amendment of this kind is likewise valid in all contracting states.
• Under Section 64 of the German Patent Law (PatG), they can request limitation in national proceedings before the German Patent and Trade Mark Office. The procedure is largely the same as that under Article 105a EPC. However, any amendment arising from national limitation proceedings is valid only in the territory of the Federal Republic of Germany.
• If the patent is contested in an action for revocation, they can defend it in amended form at first instance – before the Federal Patent Court – as well as at second instance – before the Federal Court of Justice. As in opposition proceedings, they can choose whether to restrict themselves to this line of defence or whether to propose the amendment merely as an auxiliary request. Any amendment arising from revocation proceedings is similarly valid only in the territory of the Federal Republic of Germany.

In all these procedures, an amendment's admissibility is assessed in accordance with the criteria defined in Article 123(2) and (3) EPC. While it is true that, technically, national proceedings are subject to Sections 22(2) and 21(2), sentence 1, PatG, these are identical in substance to the aforementioned EPC articles, and both are construed in the same way by the Federal Court of Justice. You should not be surprised therefore if some of the decisions I present today refer not to Article 123 EPC but only to Sections 21 or 22 PatG.

III. Extension of protection (Article 123(3) EPC)

It is my view that Article 123(3) EPC plays a much less significant role in the case law of the Federal Court of Justice than Article 123(2) EPC.

The principles governing the extension of protection are undisputed. They coincide with the concept already presented by Mr Blumer and frequently described as the "infringement test". You can read about them, for instance, in the "Wind turbine"1 decision: the protection conferred is extended where acts that do not infringe the patent as granted would infringe it as amended.

The application of these principles is rarely problematic in everyday practice. Consequently, there are relatively few decisions of the Federal Court of Justice on this issue.

From time to time, there has been debate as to whether Article 123(3) EPC precludes amendments in the equivalence range. Two scenarios especially come to mind in which this question might arise. The first is where the granted patent contains features that a particular embodiment implements only through equivalent means but these features are later amended in such a way as to be literally implemented. The second situation is where a particular embodiment does not fall within the scope of protection conferred by the granted patent but the patent is later amended in such a way that infringement by equivalent means occurs.

Unfortunately, I am unable to categorically answer this question because the Federal Court of Justice has not taken any decisions on it. Personally, I believe the answer could be that Article 123(3) EPC precludes only an extension of the literal meaning, not an extension of the equivalence range. This would mean that the amendment in the first scenario I just described would be inadmissible. In the second, the patent would be valid as amended. Nonetheless, an embodiment that was not originally covered by the patent but then fell within the equivalence range of the amended version could not constitute a ground for a guilty finding in infringement proceedings.

IV. Inadmissible extension (Article 123(2) EPC)

A question that the Federal Court of Justice has to deal with much more often is whether an amendment extends the subject-matter of the patent beyond the content of the application as originally filed.

1. Principles

In order to assess this question, the Federal Court of Justice applies the principles which Mr Blumer has already presented to you as the "magic formula" and which I have previously heard referred to as the "gold standard".

The Federal Court of Justice developed these principles in a series of judgments, recently for instance in its "Encryption techniques"2 decision. According to this decision, what matters is whether the claimed technical teaching is disclosed directly and unambiguously in the original documents as part of the invention. The original documents, as already clarified by the Federal Court of Justice on several occasions (e.g. in the "Non-replicable document"3 decision), include not only the claims formulated in the application but also the description and drawings.

2. Disclosure by drawings

The potential value of a drawing in a specific case is demonstrated by two recent decisions. Both of them are based on the principle that the drawings are as much a source of disclosure as the description and, consequently, may provide the basis for including limiting features.

Backwash filter candle

The "Backwash filter candle"4 decision related to an apparatus for filtering liquids. The patent claim stipulated inter alia that a support tube (33) was set in a partition wall (1). Both the support tube and the partition wall were described in the application. What was not expressly mentioned was that one part was set in the other. The only indication of this feature was the following drawing, which showed a support tube arranged in this way. The Federal Court of Justice considered this to be sufficient disclosure in the specific case.

Electron beam therapy system

The "Electron beam therapy system"5 decision related to a device for treating cancer patients by means of electron beams. The features listed in the patent claim included a housing (18), an electron generating means (12) and a linear accelerator (14, 16). In the course of the proceedings for grant, an additional feature was added that provided that the linear accelerator was positioned so that the generated electron beam exited it colinearly in the direction of electron travel. Although the description did not expressly mention this feature, it did indicate that a key advantage of the invention over prior-art systems was that, unlike conventional systems, no expensive equipment was needed to direct the electron beam along a curvilinear line. In these circumstances, the Federal Court of Justice considered the following drawing to be sufficient disclosure:

3. Extension, novelty and priority

That an invention must be disclosed directly and unambiguously is required not only under Article 123(2) EPC, but also – as already demonstrated by Mr Blumer – under Article 54(1) EPC. Whether the invention was already anticipated by a prior-art document also depends on whether the technical teaching claimed is directly and unambiguously disclosed in that document. The Federal Court of Justice has observed in almost all the decisions presented to you today that, to determine this, the same standards have to be applied as under Article 123(2) EPC. It also applies these standards in the context of Article 87(1) EPC, namely when deciding whether an earlier application from which priority is claimed relates to the same invention.

To rule out any misunderstandings, I would like to draw your attention once again to a distinction already highlighted by Mr Blumer: for the purposes of Article 54(1) EPC, all that matters is whether the technical teaching claimed by the patent is disclosed in the prior document. The additional requirement that the teaching must be disclosed in the prior document as forming part of the invention applies solely for the purposes of Articles 123(2) and 87(1) EPC.

4. Intermediate generalisations

It seems to me that differences between the decision-making practices of the Federal Court of Justice and the boards of appeal are most frequently reported in relation to the extent to which applicants are entitled to generalise. This is relevant where some but not all features of an embodiment are added to a claim and where certain features of a claim contained in the application are later generalised.

4.1 Incorporating certain embodiment features

According to the Federal Court of Justice's case law, applicants are, as a rule, free to single out individual embodiment features for incorporation in a patent claim. That may seem to contradict what you just heard from Mr Blumer. But here, too, the Federal Court of Justice is very clear that applicants may only ever claim combinations that the skilled person can derive from the application as filed as a possible form of the invention.

This means that the practice of "cherry picking" in particular is inadmissible. Applicants cannot draw up separate claims for features that, based on the application, are inextricably linked. Whether multiple features are inextricably linked cannot be assessed solely on the basis of the claims formulated in the application however, but rather on the basis of the content of the originally filed documents as a whole. It is therefore possible to derive from the description or the overall context of the application that forms of implementation which make use of only certain features of an embodiment are part of the invention. This may diverge somewhat from the decision-making practice of certain boards of appeal, which on occasion take a stricter view of this, not necessarily on principle, but possibly in their practical approach in individual cases.

Torque transmitting device

The "Torque transmitting device"6 decision is a good example of how the Federal Court of Justice applies these principles in practice. That decision related to a patent for a specially designed clutch for automobile engines, with features including two coaxially arranged flywheel masses that were able to rotate relative to one another. Claim 1 of the application contained an additional feature according to which the two flywheel masses were axially adjustable relative to one another, but that feature was no longer included in claim 1 of the patent as granted.

The Federal Patent Court revoked the patent for two reasons: firstly, since the application only described embodiments featuring, in addition to two flywheel masses, an energy accumulator, such an energy accumulator had to be included as a feature in the patent claim. Secondly, since the features "able to rotate" and "axially adjustable" in claim 1 of the application were inextricably linked, both features had to be included in the patent claim.

Although the Federal Court of Justice ultimately upheld the Federal Patent Court's decision, it considered its first argument invalid. Even if the application described only embodiments with an energy accumulator, it was sufficiently clear from the absence of such a feature in claim 1 of the application that embodiments without an energy accumulator were also claimed as forming part of the invention. The Federal Court of Justice endorsed, however, the Federal Patent Court's second argument. Like the Federal Patent Court, it concluded that based on the application the two features "able to rotate" and "axially adjustable" were inextricably linked and therefore neither of them could be claimed in isolation. The key factor here was not just the application's claim 1 but rather the content of the application as a whole, which at no point indicated that flywheel masses able to rotate relative to one another but not axially adjustable relative to one another would suffice.

4.2 Direct disclosure

The criteria used by the Federal Court of Justice to assess the admissibility of singling out individual features of an embodiment for incorporation in the claim are the same as those it otherwise uses for the purposes of Article 123(2) EPC. To illustrate this, I will present some recent decisions in which the court had to decide whether certain features were directly and unambiguously disclosed in the application.

Non-replicable document

The Federal Court of Justice had a somewhat complex matter to consider in the aforementioned "Non-replicable document"7 decision. That decision concerned a method for making a document using an original image comprising lines, dots or swirls. According to claim 1 of the patent as granted, the original image had to be overlaid with a grid pattern having a pitch distance slightly more or less than the scanning pitch distance in conventional photocopiers. Claim 1 of the application however provided that the lines, dots or swirls contained in the original image constituted a grid pattern having the specified pitch distance. Thus, the patent as granted neither generalised nor limited the earlier claim, but was instead directed to a different invention altogether.

The application also contained a claim 13, which related to a method for making a document by copying an original document, where the scanning pitch distance set differed from the pitch distance of the original document. The patent proprietor argued that the copy process as claimed in the application involved overlaying the original image with a grid pattern that exhibited the features of claim 1 of the patent as granted on account of heating of the paper during the copy process.

The Federal Court of Justice held that the asserted effects might conceivably occur in the method according to the application's claim 13 and that the skilled person would recognise that. Nevertheless it concluded that the method claimed in the patent as granted was not directly and unambiguously disclosed in the application. What was key, according to the court, was that the skilled person would be unable to recognise the relevant associations solely on the basis of what was stated in the patent application without giving further thought to the matter.

Polymer foam

A similar problem was dealt with in the "Polymer foam"8 decision. It concerned a process for the preparation of a foam by melt-mixing a composition of specific polymers with expandable microspheres. According to claim 1 as granted, the polymer composition was melted first and then the microspheres were added. By contrast, claim 1 as filed did not expressly specify the chronological order in which the "melting" and "mixing" process steps should take place. Nor did the description contain any explicit information on this. The patent proprietor argued that the skilled person could derive from the temperature values in the description that the
polymer composition was melted before the microspheres were added.

The Federal Court of Justice concluded that the chronological order could not be derived from the term "melt-mixing". However, it held the disclosure to be sufficient if the skilled person could readily derive from the temperature values contained in the application that the polymer composition was already melted before the mixing step. This being an unsettled point of dispute between the parties, the Federal Court of Justice referred the case back to the Federal Patent Court.

4.3 Disclosure as forming part of the invention

As I already mentioned at the outset, it is not sufficient for the purposes of Article 123(2) EPC that a specific feature is merely disclosed in the application. Rather, it must also be clear from the content of the application that it forms part of the claimed invention.

Non-UV-sensitive printing plate

The Federal Court of Justice recently dealt with this difference in the "Non-UV-sensitive printing plate"9 decision. That decision concerned the priority of a citation. As I have already mentioned and as the court stated clearly in the decision, the principles that apply in such cases are the same as those applicable under Article 123(2) EPC.

The application in question concerned a method for making a printing plate having a photosensitive composition in an alkali developer. According to claim 1 the photosensitive composition was not sensitive to UV light. The earlier application from which priority was claimed did not expressly mention that feature anywhere, but did describe embodiments using compositions which, due to their intrinsic properties, were non-UV-sensitive.

In these circumstances, the Federal Court of Justice found that priority could not be claimed. Although the lack of UV sensitivity of the compositions used in the embodiments might conceivably be immediately apparent to the skilled person and therefore be implicitly disclosed, it was not disclosed as forming part of the invention because the skilled person had been given no indication in the earlier application that a lack of UV sensitivity was significant for selecting a composition according to the invention.

4.4 Generalisations compared with the claim formulated in the application

The principle that the subject-matter of an application is determined not only by its claims but also by the description and drawings is also applied by the Federal Court of Justice in its case law on the generalisation of features.

Communication channel

The Federal Court of Justice dealt with this aspect most recently in its "Communication channel"10 decision. That decision concerned a mobile radio station having a data channel and multiple control channels configured in such a way that the start of transmission in the data channel was delayed until after the start of transmission in the control channels. Also, according to claim 1 as filed, transmission followed a specific technical procedure (frequency division duplex communication), and the control channels were used to transmit information on the basis of certain system parameters (transmit power and bit rate). As granted, however, claim 1 was directed to all transmission procedures and the transmission of any kind of control information via the control channels.

The Federal Court of Justice found the generalisation to be admissible in this particular case. The crucial factor here was that neither the description nor the embodiments in the application contained a direct reference to the frequency division duplex method or the exact type of information transmitted in the control channel. Therefore it was immediately clear for the skilled person from the application that the teaching disclosed and claimed related to delaying the transmission of information in the data channel until after transmission had begun in the control channels.

To avoid any confusion, I should clarify that the amendment would not have been admissible under Article 123(3) EPC because it undoubtedly extended the scope of protection. But that was irrelevant in the case in point because, as the amendment had already been made before the patent was granted, the Federal Court of Justice only had to examine the patent in the light of Article 123(2) EPC.

V. Conclusion

All in all, I think it is fair to say that the case law of the Federal Court of Justice and the decision-making practice of the boards of appeal are not based on different principles, but at most on differences in how these principles are applied in individual cases. I very much hope you agree with me. But even if you do not, I look forward to the discussions to follow and to seeing how the Federal Court of Justice and the boards of appeal go on to develop the case law.