G 0001/91 (Unity) of 9.12.1991

European Case Law Identifier: ECLI:EP:BA:1991:G000191.19911209
Date of decision: 09 December 1991
Case number: G 0001/91
Referral: T 0220/89
Application number: 80103866.2
IPC class: C25B 1/00
Language of proceedings: DE
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Documentation of the appeal procedure can be found in the Register
Bibliographic information is available in: DE | EN | FR
Versions: OJ
Title of application: -
Applicant name: Siemens
Opponent name: Kernforschungszentrum Karlsruhe
Board: EBA
Headnote: Unity of invention (Article 82 EPC) does not come under the requirements that a European patent and the invention to which it relates must meet under Article 102(3) EPC when the patent is maintained in amended form. It is consequently irrelevant in opposition proceedings that the European patent as granted or amended does not meet the requirement of unity.
Relevant legal provisions:
European Patent Convention 1973 Art 82
European Patent Convention 1973 Art 102(3)
European Patent Convention 1973 R 61a
Keywords: Unity in opposition - legally irrelevant


Cited decisions:
Citing decisions:
G 0003/14
T 0220/89
T 0234/90
T 0551/90
T 0287/91
T 0524/91
T 0868/91
T 0195/92
T 0402/92
T 0463/95
T 0883/95
T 0245/96
T 0443/97
T 0579/97
T 1013/97
T 0314/99
T 0598/99
T 1081/02
T 0263/05
T 0106/06
T 0172/06
T 0339/06
T 0079/07
T 0993/07
T 1495/09
T 1577/10
T 0548/11
T 0830/11
T 0037/12
T 0115/12
T 0066/14
T 0318/14
T 2099/15
T 0146/16
T 1661/16
T 1835/17
T 2117/17
T 0647/18
T 0806/18
T 1417/18
T 0571/19
T 0929/19

Summary of the Proceedings

I. Notice of opposition to European patent No. 0 023 585 (application No. 80 103 866.2) was filed on the ground of lack of inventive step. In the oral proceedings before the Opposition Division the need to compose new claims was raised and it was mentioned in passing that "the question of unity in opposition proceedings" was "not under discussion". The interlocutory decision of the Opposition Division dated 1 February 1989 established that the European patent could be maintained with amended documents and the description adapted accordingly.

II. The Opponent filed an admissible appeal against this decision, without going into the question of unity. However, in a subsequent letter dated 14 January 1991, it drew attention exclusively to lack of unity, concluding that in opposition proceedings amendments to the contested patent were not permissible if they would result in lack of unity. The Board of Appeal thereupon informed the parties that it intended to refer the point of law raised by the Opponent to the Enlarged Board of Appeal. The patent proprietor described the Opponent's remarks as unfounded and a referral to the Enlarged Board of Appeal as inappropriate, one reason being that unity did in fact exist.

III. In interlocutory decision T 220/89 dated 28 February 1991 (OJ EPO 1992, 295) Technical Board of Appeal 3.4.2 referred the following point of law to the Enlarged Board of Appeal: Even if Article 82 EPC refers to a European patent application and Article 100 EPC does not give unity of invention as a ground for opposition, does application of Rule 61a EPC (cf. in particular Rules 27, 29 and 30 EPC) in the case of an amended European patent mean that the unity of invention demanded by Article 82 EPC comes under the "requirements of this Convention" mentioned in Article 102(3) EPC which the patent maintained in amended form must meet? According to the interlocutory decision, the question whether unity of invention within the meaning of Article 82 EPC comes under the requirements of the Convention to be examined in accordance with Article 102(3) EPC when the patent is amended arises primarily for the following reasons:

1. Rule 61a EPC lays down that "Part III, Chapter II, of the Implementing Regulations" (i.e. Rules 26 to 36 EPC) shall apply to new documents filed in opposition proceedings. These Rules refer to the invention in the singular. It could be inferred from this that they are based on the assumption of a single invention.

2. Rule 61a applies in particular to Rule 30 EPC. New documents filed in opposition proceedings therefore have to meet the requirement of unity.

3. It is apparent from Board of Appeal practice that new documents filed in opposition proceedings are examined for "clarity" within the meaning of Article 84 EPC. This raises the question as to why Articles 82 and 84 EPC should be regarded differently in opposition proceedings. Both Articles could in fact also be taken to refer to the preceding Article 78 EPC and would thus apply only to the European patent application prior to grant of the patent and not to the European patent in opposition proceedings. The referred decision T 220/89 concludes that an explanation is required as to how to interpret Article 102(3) EPC with regard to Article 82 EPC when applying Rule 61a EPC.

Reasons for the Decision

1. On the admissibility of the referral The referral of the point of law is admissible under Article 112 EPC. Some previous decisions have regarded the requirement for unity as unimportant in opposition proceedings (T 162/85; T 437/88; T 49/89) or as having been fulfilled and therefore irrelevant (T 539/88). The answer to the question raised here is not obvious, as is clear from the fact that Section 26 of the United Kingdom Patents Act expressly states that a patent may not be impugned for lack of unity. The legal significance of unity of invention in opposition proceedings under the European Patent Convention is therefore an important point which needs to be clarified, not least to ensure uniform application of the law.

2. Interpreting Article 102(3) EPC on the basis of its wording

2.1 In resolving the point of law raised it is not Rule 61a EPC which is of prime importance, but Article 102(3) EPC. This Article stipulates that, when the patent is maintained as amended, "the patent and the invention to which it relates (must) meet the requirements of this Convention". This could at first be taken to mean that every single requirement of the Convention must be met. Such an interpretation is also borne out by the fact that Article 102(3) EPC contains exactly the same wording as that chosen for Article 94(1) EPC with regard to the European patent application. 2.2 The wording of the provisions referred to above, however, also gives grounds for concluding that the requirements which an amended patent must meet are not necessarily the same as those demanded of a patent application, although that only justifies excluding those "requirements" under Article 102(3) EPC which it would be unreasonable to apply to the patent as well as to the patent application. This cannot be said of the requirement for unity of invention.

3. The possible contribution of Rule 61a EPC to interpreting the term "requirements" in Article 102(3) EPC

3.1 Recourse may be had to implementing provisions - even those established subsequently such as Rule 61a EPC - in order to interpret contractual rules (cf. Art. 31(3)(b) of the Vienna Convention on the Law of Treaties, OJ EPO 1984, 196). However, it cannot be concluded from Rule 61a EPC that "unity" within the meaning of Article 82 EPC should be demanded of a European patent.

3.2 Rule 61a EPC refers in general terms to "Part III, Chapter II, of the Implementing Regulations" which "shall apply mutatis mutandis to documents filed in opposition proceedings". However, this Rule can only be taken to refer to those requirements which it would still be reasonable to demand of the new documents relating to the amended patent. Just because "invention" is used in the singular in Rules 27 (Content of the description) and 29 (Form and content of claims) does not mean that unity is required. This is a case of the use of "singular for plural", a device used frequently in legal texts whereby the singular (in this case: "invention") can also refer to a plural (in this case: "group of inventions" within the meaning of Article 82 EPC). The Rules in question therefore also apply when - because there is no lack of unity - more than one invention is claimed and described in one patent application.

3.3 Taken literally, Rule 61a EPC refers only to regulations governing "documents" and cannot therefore refer to Rule 30 EPC since the latter is not concerned with the form and content of documents but with establishing a rule of law for interpreting Article 82 EPC. This is made particularly clear in the earlier version of Rule 30 EPC ("Article 82 shall be construed as ..."), but also in the new version (in force since 1 June 1991).

3.4 Thus, although Rule 61a contains a general reference to a chapter of the Implementing Regulations, it is clearly not intended to apply to certain rules (for example, Rules 26, 31 and 33, as well as 30) but only to others (such as Rules 27, 29, 32 and 34). The Interim Committee of the European Patent Organisation, which prepared the insertion of Rule 61a EPC, noted with regard to the general reference "that certain provisions of this Chapter were clearly not applicable to documents in opposition proceedings"; it felt "however ... that it would be preferable to adopt a general text in view of the complexity of the matter" (CI/Final 11/77 dated 14 October 1977).

3.5 Rule 61a EPC, which was inserted subsequently into the Implementing Regulations, thus makes it clear that the requirements laid down in Rules 26 to 36 EPC for patent applications must also apply mutatis mutandis to documents filed in opposition proceedings. However, no conclusion can be drawn from Rule 61a EPC which would clarify the point of law raised concerning unity.

4. The intention behind unity on the one hand and of opposition proceedings on the other

4.1 Although unity of invention under Article 82 EPC is a material requirement, it is still merely an administrative regulation. It serves a number of administrative purposes, particularly in demarcating the respective responsibilities of the departments concerned with search, examination, opposition and further procedure. As is well known, the International Patent Classification is used in these departments for classifying documentation on the state of the art. However, the classification also serves as guidance to competitors keeping track of patent office publications. And the financial aspect prior and subsequent to grant of the patent - in other words, the amount of procedural and renewal fees both for patent applications and for the subsequent patents - is also important.

4.2 However, the administrative purposes of unity are fulfilled in the main up to the time the patent is granted. The purpose and intention of opposition proceedings is to give a competitor the opportunity of opposing unjustified protective rights. Since this serves the competitor's interests, he need not also be given the opportunity of contesting a patent on the ground of lack of unity. Lack of unity does not in fact rule out patent protection; it can only result in an application being divided to produce two or more patents. In view of the object and purpose of both unity and opposition, it seems neither necessary nor appropriate to continue to attach importance to any lack of unity at the opposition stage. Once the examination procedure has been concluded with the grant of a patent, the requirement of unity has fulfilled its administrative function.

5. Considerations regarding the legal framework

5.1 As long as unity is a requirement to be met under the patent law procedure, there must also be the possibility of establishing the required unity, either through partial surrender or division. Where division is no longer possible, lack of unity can have no further legal significance. The European patent law system does not provide for division once the patent has been granted. So even though Article 102(3) and Rule 61a EPC may leave some doubts as to the importance of unity at the opposition stage, the lack of the legal institution of division shows that unity can no longer have any importance for the opposition or in opposition proceedings.

5.2 There is consequently no need to consider how to justify the fact that EPO practice attaches a certain degree of importance to clarity within the meaning of Article 84, second sentence, EPC at the opposition stage, but none to unity under Article 82 EPC. Both regulations belong to a series of provisions - from Article 81 (Designation of the inventor) to Article 85 (The abstract) - which vary greatly in relevance to the granted patent, if they retain any relevance at all. There is therefore no contradiction in the fact that, when the patent is amended in opposition proceedings, unity no longer has any relevance, but the amended texts are still required to be clear. What exactly is to be understood by clarity within the meaning of Article 84, second sentence, EPC need not therefore be discussed in this context.

6. Evidence from the travaux préparatoires ("historical documentation") 6.1 Although the point of law in question can be clarified for certain by interpreting the Convention on the basis of its wording and rationale, it would still be useful to consult the historical documentation as well.

6.2 The 1970 First Preliminary Draft of the European Patent Convention was the first to refer to post-grant opposition. The concept was developed further in 1971 (cf. BR/87/71 dated 28 February 1971, points 6-9, and BR/135/71 dated 17 November 1971, points 133-140, and the Reports on the 1971 Second Preliminary Draft, point 59 et seq., particularly points 67-69). According to these documents the examination of the opposition - covered by today's Article 102(1) and (2) EPC - should first look at the grounds therefore - covered by Article 100 EPC. Only if these call for the patent to be amended is it necessary to examine the new documents not only in the light of the grounds for opposition but also to see whether they meet "the requirements of the Convention". According to the Report on the 6th meeting of Working Party I (BR/87/71, point 12), the intention was to prevent the EPO from being "able to object to all formal deficiencies as well as to any lack of unity of the invention protected". The Report added that a provision relating to division was therefore "not necessary". In the former system of pre-grant opposition, the division of the patent application was still possible even at the opposition stage on the basis of a special provision. The Report on the 1971 Second Preliminary Draft (point 69) states that in the opposition no objection may be made to a European patent on the ground of lack of unity, nor may the patent be divided, since it would then be necessary to publish more than one new European patent specification and translation thereof pursuant to Article 65 EPC.

6.3 The travaux préparatoires indicate, therefore, not only that lack of unity was deliberately excluded as a ground for opposition, but also that any lack of unity arising during opposition proceedings as a result of amendment of the patent must be accepted.


For these reasons it is decided that the question of law referred to the Enlarged Board of Appeal is to be answered as follows: Unity of invention (Article 82 EPC) does not come under the requirements which a European patent and the invention to which it relates must meet under Article 102(3) EPC when the patent is maintained in amended form. It is consequently irrelevant in opposition proceedings that the European patent as granted or amended does not meet the requirement of unity.

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