一覧に戻る The Boards of Appeal about Double Patenting

In the decision T 307/03, a Technical Board of Appeal of the European Patent Office discussed the principle of prohibition of double patenting. In particular, this decision relates to the questions

1. as to whether the principle of prohibition of double patenting is applicable under the European patent convention, and

2. as to whether the double patenting prohibition is applicable in a case where the later claim is more broadly formulated.

1. With respect to the question as to whether the principle of prohibition of double patenting is applicable under the European patent convention, the Board came to the conclusion that this principle (namely that the inventor (or his successor in title) has a right to the grant of one and only one patent from the European Patent Office for a particular invention as defined in a particular claim) is applicable under the EPC. This opinion had been deduced from the provision of Art. 60 EPC stating that "the right to a European patent shall belong to the inventor or his successor in title". Considering the wording of Art. 60 EPC, the Board argued that it is regarded to be evident that the inventor (or his successor in title) has a right to the grant of one and only one patent.

According to our understanding, the above argumentation appears to be rather far-fetched, since the wording of Art. 60 EPC is surely not intended to have the meaning alleged by the Board of Appeal. Nevertheless, the Board comes to a reasonable conclusion, namely that there should be a prohibition of double patenting. In this context, it is noted that although the prohibition of double patenting is not explicitly mentioned in the European patent convention, it is an accepted principle in most patent systems that two patents cannot be granted to the same applicant for one invention (cf. also the Guidelines for Examination in the EPO, Chapter C-IV, section 7.4).

2. With respect to the question as to whether the double patenting prohibition is applicable in a case where the later claim is more broadly formulated, the Board came to the conclusion that a double patenting objection can be raised also where the subject matter of the granted claim is encompassed by the subject matter of the claim later put forward, that is where the applicant is seeking to re-patent the subject-matter of the already granted patent claim, and in addition to obtain patent protection for other subject-matter not claimed in the already granted patent.

In particular, where the subject matter which would be double patented is the preferred way of carrying out the invention both of the granted patent and of the pending application under consideration, the extent of double patenting cannot be ignored as de minimis. To avoid the objection of double patenting the claims of the pending application should be confined to the other subject-matter that is not already patented, to allow the examination procedure to focus on whether a claim to this other subject-matter meets the requirements of the EPC.

According to our understanding, the above decision seems prima facie to be very surprising, since it contradicts previous European patent practice, namely that a divisional application may contain a claim which is broader than the respective claim of the corresponding parent application.

However, considering the concrete case underlying the above decision, said decision is understandable. In particular, in the above case concerning the divisional application, one of the components of a double metal cyanide complex was defined to be "a water-soluble alcohol", instead of "a water-soluble aliphatic alcohol", as defined in the parent application. Although being formally slightly broader than the original claim, it seems to be reasonable that this small difference (namely that the alcohol may also be a non-aliphatic alcohol) is not sufficient to justify the grant of another patent.

In view of the above, it appears that the statement of the decision under discussion, that the principle of double patenting prohibition is applicable in a case where the later claim is more broadly formulated, should be applied at least in cases where the difference in the scope between the parent application and the divisional application is negligible. However, we see presently no reason to deviate from previous European patent practice, i.e. that a divisional application may contain a claim which is broader than the respective claim of the corresponding parent application, if there is a significant difference in the scope of said claim of the divisional application compared to the parent application.

Download the full text of the decision T 307/03 "ARCO/Double patenting" of the BoA of the EPO under:

http://www.mueller-bore.de/tl_files/Decisions_EPO/ARCO_Double_Patenting.pdf

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