T 0274/00 (Process for cooking/browning food/WHIRLPOOL) 16-06-2004

Reasons for the Decision

1. The appeal is admissible.

Background and introductory remarks

2. The substantive provision set out in Article 123(3) EPC (prohibition of extension of protection) is specifically limited in its application to the amendment of claims in opposition proceedings before the EPO ("The claims of the European patent may not be amended during opposition proceedings in such a way as to extend the protection conferred.").

2.1. This article is directly aimed at protecting the interests of third parties by prohibiting any broadening of the claims of a granted patent, even if there should be a basis for such broadening in the application as filed (see G 1/93, OJ EPO 1994, 541). The guiding principle under Article 123(3) EPC may therefore be summarised by the finding that "once a European patent has been granted, an act by a third party which would not infringe the patent as granted should not be able to become an infringing act as a result of amendment after grant". This is the essential purpose and guiding principle underlying Article 123(3) EPC (see eg T 1149/97, OJ EPO 2000, 259).

2.2. It follows that, when considering Article 123(2) EPC, the question of extension of subject-matter depends upon a comparison with the "application as filed". When considering Article 123(3) EPC, however, the question of extension of the protection conferred depends upon a comparison with the "claims as granted".

2.3. When considering whether a proposed amendment to the claims is such as to extend the protection conferred

- a first step must be to determine the extent of protection which is conferred by the claims as granted before the amendment: it is necessary to be quite clear as to what is the protection conferred by the claims without amendment, before one can decide whether a proposed amendment is such as to extend it;

- the second step to be considered under Article 123(3) EPC is then whether the subject-matter defined by the claims is more or less narrowly defined as a result of the amendment. A proposed amendment may involve a change of category, or a change in the technical features of the invention, or both. Each type of amendment requires separate consideration. In the present case of a change in the technical features of the invention, if the technical features of the claimed invention after amendment are more narrowly defined, the extent of the protection conferred is less; and if such technical features are less narrowly defined as a result of amendment, the protection conferred is therefore extended. Clearly, if technical features are changed by an amendment, in that the subject-matter of the claims after amendment is outside the scope of the subject-matter before amendment, there is then necessarily an extension of protection (see G 2/88, G 6/88, OJ EPO, 1990, 93, 114).

Interpretation of claims under the EPC

3. The EPC contains a set of provisions (Article 84 and Rule 29(1) EPC in conjunction with Article 69 EPC and its Protocol) which reflect the central importance of the claims of a European patent application or patent for determining the scope of protection conferred by it.

3.1. Determination of the extent of protection has to be carried out in accordance with Article 69(1) EPC and its Protocol. The protection conferred by a patent is determined by the terms of the claims (Article 69(1) EPC and its Protocol), and in particular by the categories of such claims and their technical features. The main role of the claims is emphasised in the first sentence of Article 69(1) EPC. The subsidiary role of the description and the drawings is set out in the second sentence of said Article. The nature of the relationship between the claims on the one hand, and the description and the drawings on the other hand is further explained in the Protocol to Article 69 EPC which provides a guide to the manner in which the technical features of the claim are to be interpreted, if necessary.

3.2. The object of the Protocol, which provides a guide to the manner in which the technical features of the claim are to be interpreted, is clearly to avoid too much emphasis on the literal wording of the claims when considered in isolation from the remainder of the text of the patent in which they appear; and also to avoid too much emphasis upon the general inventive concept disclosed in the text of the patent as compared to the relevant prior art, without sufficient regard also to the wording of the claims as a means of definition. This approach to the interpretation of claims must be adopted by the EPO when determining the protection conferred for the purpose of Article 123(3) EPC.

Extent of protection conferred before the amendment

4. The application of the principles set forth above to the present case leads to the following conclusions:

4.1. The extent of protection conferred by the broadest claim of the patent in suit, ie claim 1 as granted, encompasses "A method for browning/crusting food, in two stages, comprising: "In a first stage: placing a microwave-lossy browning/crusting device in a microwave chamber, said browning/crusting device including a metal food contacting surface on a metal tray supporting a non-metal food contacting surface ........... ."

4.2. The aforementioned technical features defining the browning crusting device, when being read with the normal skills including the knowledge about the prior art, are in their technical meaning in the given context sufficiently clear in themselves that they can be used to determine the extent of protection without interpretation by reference to the description and the drawings of the patent. The skilled reader would immediately understand that said browning/crusting device includes in its broadest aspect as claimed in claim 1 as granted a metal food contacting surface on a metal tray and a non-metal food contacting surface supported by that metal tray. In this respect it should be noted that neither the examining division during the examination proceedings, nor the opposition division during opposition proceedings indicated that there had been a problem understanding the technical meaning of the features of claim 1 as granted in the given context. On the contrary, from the opposition division's reasoned statement in the decision under appeal to the effect that claim 1 as granted lacks novelty over the state of the art according to citation (1) it would seem that it was in itself in no real doubt as to the clarity of the technical meaning of the claim in question in its given context.

4.3. In particular, the wording and terminology of the features used in claim 1 of the patent in suit are sufficiently clear and technically meaningful to exclude the interpretation given by the opposition division in paragraph 2 of the decision under appeal, namely "that claim 1 would be interpreted by the skilled person as meaning nothing else than that either a metal food contacting surface or a non-metal food contacting surface is contacted by the food. That nothing else than that was intended by drafting the claim has also been confirmed by the proprietor of the Patent."

The wording of claim 1, on its proper construction (ie when its meaning for the skilled man is determined), leaves no room for the interpretation by the opposition division according to which this claim would cover, beyond its wording, two distinct alternatives for the browning/crusting device, that is to say a first alternative of a browning/crusting device which includes only a metal food contacting surface and a second alternative including only a non-metal food contacting surface. On the contrary, the wording and terminology used in the granted claim clearly stipulate the use of a browning/crusting device including both

- a metal and

- a non-metal food contacting surface, the latter being supported by a metal tray.

4.4. In the decision under appeal (see Reasons, point 2, last two paragraphs) the opposition division emphasised "that the embodiment of figure 6 shows a device having both materials (emphasis added by the board) as food contacting surface. In connection with this, it is considered that the rim of the metal tray in the embodiment of figure 6 is small, but still a surface which can be contacted by the food. Thus even by applying a strict literal interpretation of the wording of the claims support can be found in the description" (emphasis added by the board).

Although the above observations of the opposition division regarding the embodiment shown in Figure 6 (and similarly the embodiments shown in Figures 3 to 5 of the patent in suit) appear correct, namely that in the above-mentioned figures devices are shown "having both materials as food contacting surface" (ie a metal and a non-metal food contacting surface, these observations do not, of course, support the opposition division's attempt to interpret claim 1 as granted "as meaning nothing else than that either a metal food contacting surface or a non-metal food contacting surface is contacted by the food".

On the contrary, when using, in accordance with Article 69 EPC and its Protocol, the description and drawings, in particular Figures 3 to 6 in the context of the disclosure in column 6, lines 53 to 57, of the patent, to determine the subject-matter which is protected by claim 1, as defined by its technical features before amendment (emphasis added), the opposition division itself concluded that the patent confers protection on a browning/crusting device "having both materials as food contacting surface", ie a metal and a non-metal food contacting surface.

4.5. During the oral proceedings before the board the respondent argued that the amendment did not offend Article 123(3) EPC because it served to remove an inconsistency between claim 1 and dependent claim 4 as granted (see I above). Such an inconsistency was, however, neither mentioned by the examining division during the examination proceedings or by the opposition division during opposition proceedings, nor can the board find the alleged inconsistency.

In this respect it is noted that, by using the terminology "including" (claim 1), "includes" (claim 4), the definition of the browning/crusting device is open-ended in both claims 1 and 4.

The relevant portion of claim 1 reads as follows: "said browning/crusting device including a metal food contacting surface on a metal tray supporting a non-metal food contacting surface";

The relevant portion of claim 4 reads as follows: "said browning/crusting device includes a metal plate which has a metal food contacting surface and has a microwave-lossy composition in contact with the opposite surface of said food contacting surface".

By purposely choosing the terminology "including" or "includes" the respondent made it, in the board's judgment, unambiguously clear that neither in claim 1 nor in claim 4 as granted the browning/crusting device had ever been intended to be restricted to one alternative only, namely that either a metal food contacting surface or a non-metal food contacting surface is present on said browning/crusting device. According to "Webster's Ninth New Collegiate Dictionary", Springfield, Mass, 1987, page 609, "syn include, comprehend, embrace, involve mean to contain within as part of the whole. Include suggests the containment of something as a constituent, component, or subordinate part of a larger whole."

The board cannot thus agree with the respondent's argument that claim 4 relates to an embodiment (alternative) of the claimed invention, excluding a non- metal food contacting surface as a compulsory component of the browning/crusting device as defined in claim 1. On the contrary, dependent claim 4 could, in the board's opinion, only be interpreted by the skilled reader as relating to a specific embodiment of the metal food contacting surface mentioned in claim 1 as one component of the browning/crusting including both a metal food contacting surface and a non-metal food contacting surface as stipulated by claim 1.

The notional skilled person, familiar with the basic principles of patent law, would arrive at the following wording of claim 1 when including the features of claim 4:

"said browning/crusting device including a metal plate which has a metal food contacting surface and has a microwave-lossy composition in contact with the opposite surface of said food contacting surface on a metal tray supporting a non-metal food contacting surface".

In view of the above, the board sees no sound reason justifying the deletion of the features "on a metal tray supporting a non-metal food contacting surface" in claim 1 as amended, when including in the claim the subject-matter of dependent claim 4, even when applying the principles of Article 69 and its Protocol.

4.6. During the hearing before the board, the respondent argued for the first time in the present case that the relevant wording in claim 1 as granted ".......... metal food contacting surface on a metal tray ............." resulted from an unintentional transcription error for "......... metal food contacting surface or a metal tray ............"

In order to make credible an obvious error in a document filed at the EPO, two matters must be established:

(i) that an error is indeed present in that document;

(ii) that the proposed correction of the error is obvious in "in the sense that it is immediately evident that nothing else would have been intended than what is offered as the correction".

4.7. In order to establish condition (i), which is a subjective matter, reference may be made to any relevant documents or other evidence, including in appropriate cases the file history (see in this connection, inter alia, decision J 4/85, paragraph 7, third sub-paragraph, OJ EPO, 1986, 205). In the present case, in the board's view, having regard to the file history, there is absolutely no indication that the text of the granted version of claim 1 might indeed have resulted from the above-mentioned unintentional transcription error. In this respect reference is made, inter alia, to the following relevant episodes of the file history:

- the text of the claims and the description as granted and the drawings are identical with the corresponding parts of the application as originally filed, ie the international application as published under the PCT (WO 92/14369);

- the respondent's unambiguous approval with its letter of 10 May 1995 to the text of the claims and the description as granted and the drawings accompanying the Rule 51(4) EPC communication dated 27 February 1995 ("In connection with the above application, the applicant approves the text and drawings accompanying the Rule 51(4) Communication dated 27th February");

- the respondent's sole request in the written opposition proceedings on 18 September 1998 that the patent be maintained in the form as granted;

- the repetition of the above request as the main request in the oral proceedings before the opposition division;

- the finding of the opposition division in the decision under appeal that claim 1 as granted lacked novelty over the prior art of (1);

In view of the above, no indication can be found on the basis of the file history that claim 1 as granted contained the alleged unintentional transcription error. In the board's opinion, the alleged error could not have remained unnoticed by the respondent until such a late stage of the appeal proceedings.

4.8. As regards condition (ii), the observations in points 4.1 to 4.5 above made it sufficiently clear that a skilled reader of the granted patent would not have recognised that nothing else would have been intended by the respondent than what it offered as the correction during oral proceedings before the board.

5. Conclusion: In view of the above, there can be no doubt that the technical features of the claimed subject-matter in claim 1 as amended after grant are less narrowly defined as a result of the proposed amendments and that the protection conferred is therefore extended. Clearly, the technical features have been changed by the proposed amendment, in that the technical subject-matter of claim 1 after amendment is outside the scope of the technical subject-matter before amendment and there is then necessarily an infringement of Article 123(3) EPC.