T 1248/08 – What’s Your Number?

This is an appeal against the revocation of the European patent under consideration.

Claim 1 of the patent as granted read:

A coating solution for forming a film for cutting off heat radiation which contains fine particles of at least one hexaboride and fine particles of tin-containing indium oxide (ITO) or antimony-containing tin oxide (ATO), in a weight ratio of from 0.1:99.9 to 90:10, said hexaboride being represented as XB6 where X is Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sr or Ca provided that, when the hexaboride is LaB6, the weight ratio of LaB6 to ITO or LaB6 to ATO is not 18.6:81.4.

Claim 1 of the main request before the Board read:

A coating solution for forming a film for cutting off heat radiation which contains fine particles of LaB6 and fine particles of tin-containing indium oxide (ITO) or antimony-containing tin oxide (ATO), provided that the weight ratio of LaB6 to ITO is from 0.62:99.38 to 10.7:89.3 and the weight ratio of LaB6 and ATO is from 1.10:98.9 to 13.8:86.2. (my emphasis)

The opponent raised objections under A 123(2) against the value of LaB6/ITO of 0.62:99.38, which was based on the alleged disclosure of 0.09 for the LaB6 concentration. According to the opponent, this value was not unambiguously derivable from the application documents as originally filed.

The patent proprietor considered that the proposed value of “0.09” in example 1 of Table 1 was allowable because it was clearly and unambiguously derivable from the application documents as originally filed.

Moreover, the value was indirectly derivable from the plotted points in Figure 2 at the position x = LaB6 /(LaB6 + ITO) = 0.06 which agreed with the proposed value of 0.09 for the hexaboride concentration, but not with alternative values of “0.08” or even “0.05”.

The opponent argued that the scale of the axes and the plotted points in Figure 2 made it impossible to distinguish between 0.62% and 0.55%, and hence it could not be used to confirm the value of 0.09 in example 1 of Table 1.

The Board agreed with the opponent:

Amendments (A 123(2) and (3))

Main request […]

[1.1.1] In the application as filed (page 24, Table 1, first row, second column), a number pertaining to the value of the amount of the Lanthanum hexaboride used in example 1 was illegible and indecipherable. It was not clear whether it should read “0.08” or “0.09”, or even “0.05”.

The board is not persuaded by the appellant’s arguments that the actual disclosure of that figure was unequivocal and that it reads “0.09”.

According to the board, said value, in particular the number “9” thereof, is neither directly and unambiguously derivable from said Table 1 […] because the entry in question is so poorly legible that it may be interpreted as “0.08” or as “0.09” or even as “0.05”, nor can it be derived in an unambiguous manner from the position on the abscissa of the corresponding data points on the graph of example 1 in Figure 2 as filed. To avoid any ambiguity, a higher degree of accuracy would be required so that the position of the plotted points could be ascertained with a precision of as little as 0.07. Such a precision is, in the board’s opinion, impossible to achieve in view of the scale of the abscissa of Figure 2 and in view of the fact that the data “points” are represented by circles having themselves a diameter of at least about 0.05.

The application documents as originally filed are therefore ambiguous in this respect.

[1.1.2] In accordance with the established jurisprudence of the Boards of Appeal of the EPO, and contrary to the assertions of the appellant, in the case of a proposed amendment under A 123(2) or of a correction under R 139, the factual disclosure of a European patent application as originally filed has to be established to a rigorous standard, namely the standard of certainty “beyond reasonable doubt” (see T 113/86 [2.2]; T 383/88 [2.2.2]; T 581/91 [3, last three paragraphs]; T 723/02 [2.4]; T 1239/03 [3.3.3]). In the above-cited decisions, the boards explicitly rejected the “balance of probabilities”, the normal standard of proof in civil proceedings, as an appropriate criterion to be applied. In particular, it was decided in T 113/86 that

“amendments requested by the Patentee should not be allowed if there was the slightest doubt that the unamended patent could be construed differently to the patent as amended”.

In T 383/88 the board remarked that

“applying a lower standard could easily lead to undetected abuse by allowing amendments on the basis of ostensibly proven common general knowledge.”

[1.1.3] The board considers that the above-cited jurisprudence is eminently important and clearly applicable to the present case, where an analogous question of compliance or non-compliance with the requirements of A 123(2) needs to be decided, namely the question of whether a particular proposed feature is disclosed in the application documents as originally filed. Following the established jurisprudence, the board considers that the balance of probabilities is not an acceptable standard for determining the actual value and that this question should be [determined] on the basis of the rigorous standard of certainty characterised as “beyond reasonable doubt”. Therefore, the arguments of the appellant adopting a proof “on the balance of probability” in favour of the value of “0.09”, in particular the survey A6, must fail. According to this survey – conducted amongst partners and staff at Withers & Rogers LLP (the firm of the [patent proprietor’s] representative) – out of 72 test persons, a total of 67 indicated the relevant entry in Table 1 to be “0.09” without qualification. However, it was also found that two respondents indicated another figure (“0.08”) and that three further respondents who indicated “0.09” had also considered other possibilities. In the board’s opinion, therefore, these results demonstrate that the value in question cannot be considered to be “0.09” with a certainty “beyond reasonable doubt”, as required by the established jurisprudence. In any event, a question of accuracy and disclosure cannot be decided by a poll.

[1.1.4] The appellant also pointed to the priority document of the patent in suit and to the family patent document A8 (published 20 November 2001) as potential sources of supplemental original disclosure. This approach must fail, because the Enlarged Board of Appeal (EBA) ruled in decision G 11/91 [7] that

“[b]efore a correction can be made under R 88, second sentence, it has to be established in point of fact what actually a skilled person would derive, on the date of filing, from the parts of the European patent application relating to the disclosure. As a result of the prohibition of extension under A 123(2), documents other than the description, claims and drawings may only be used insofar as they are sufficient for proving the common general knowledge on the date of filing. On the other hand, documents not meeting this condition may not be used for a correction under R 88, second sentence, even if they were filed together with the European patent application. These include, inter alia, priority documents, the abstract and the like.” (emphasis added).

Therefore, the disclosure of the priority document cannot be used to supplement or replace parts of the disclosure of the application as originally filed. Nor can it be used to dispel doubts as to the meaning of an ambiguous part of the application.

The same applies to the family documents, for the reason that the text of another patent application based on the same priority document need not be identical to the European patent application.

[1.1.5] In view of the above reasoning, the lower limit of the ratio of LaB6 to ITO of 0.62:99.38 […] and derived from a weight ratio of 0.09 to 14.5 (Table 1, example 1) is not disclosed in the originally filed documents.

For comparison only, a weight ratio of 0.8 to 14:5 in example 1 would yield the weight ratio of 0.55:99.45.

The board observes that an amendment to 0.55:99.45 would also not be allowable because of a lack of a clear and unambiguous disclosure of the concentration value of 0.08 in Table 1 as originally filed.

The requirements of A 123(2) and (3) are thus not met. The main request [… is] not allowable.

Should you wish to download the whole decision, just click here.

The file wrapper can be found here.

NB : The decision has already been reported on Le blog du droit européen des brevets (here).