Oldies But Goldies - Proof For Prior Use

As new decisions are scarce these days, I have decided to follow a suggestion that a member of the Boards has made to me not long ago. It is an idea I had had in the past but which I had never reduced to practice because back then I was snowed under with fresh decisions. The idea is to present old decisions which are still cited today but which not all of those who cite them have actually read. So, from time to time, I shall present key passages of such decisions. Feel free to let me know whether you like the idea or not.

Of course, there are some risks in presenting old case law, because the EPC has changed here and there and some statements may simply be obsolete. Also, my knowledge of case law is limited and I might miss relevant decisions. Should I fall into one of those traps, please leave a comment.

I have decided to start with decisions mentioned in my previous post – decisions that deal with prior use and the standard of proof required for establishing the reality of such a use.

T 270/90 is a relatively early decision (March 21, 1991) of Board 3.3.3 tackling the question of which standard is to be applied. The Board nicely summarised the “balance of probability” principle developed in earlier decisions (e.g. T 381/87 and T 182/89) and then applied it to prior uses:

[2] [… T]he objection of lack of novelty boils down to an objection of prior public use based on the analytical results of Noryl samples submitted by the [opponents].

[2.1] In relation to the issue of prior use the [patent proprietor] strongly argued that, as a matter of law, this ground of objection needed to be proved more strictly than any of the other grounds of objection available under A 100. Indeed, he went so far as to say that the evidential test for establishing prior use under the EPC must be at least as strict as the strictest of tests applied by any of the relevant judicial organs of the Contracting States. In effect, he submitted that prior use had to be established not on the balance of probability but beyond reasonable doubt, that is to say established with the same degree of strictness as applies, for example, to criminal proceedings in the United Kingdom.

The Board wishes to restate the principles of law that apply to appeal proceedings under the EPC, for these principles are tacitly assumed in many cases, but are seldom expressly spelt out.

The Boards of Appeal are judicial bodies, adjudicating, in the case of oppositions, in contentious civil matters. The matters are contentious because there is an opposition to a granted patent, and they are civil because they pertain to a species of intellectual property. Although it is true that the Boards are possessed of inquisitorial powers (A 114(1)), these powers do not convert them from judicial into administrative tribunals.

In consequence, when arriving at their decisions, the Boards, in addition to exercising their inquisitorial powers (should this be necessary), decide the issues before them on the basis of the evidence adduced by the parties. Their decision need not, and indeed in most cases could not, be based on absolute conviction, but has, instead, to be arrived at on the basis of the overall balance of probability, in other words, on the footing that one set of facts is more likely to be true than the other (see decision T 182/89).

As far as each of the parties to the proceedings is concerned, they carry the separate burdens of proof of any fact they allege. The weight of that burden is the balance of probability as distinct from “beyond all reasonable doubt” or “absolute conviction”. In the course of an appeal, therefore, each party must seek to prove facts alleged by it to this degree of proof and, as was said above, it is the function of the Board to decide, applying the same standard, which set of facts is more likely than the other to be true.

These principles clearly apply to all facts and matters alleged in relation to all grounds of opposition, including public prior use. Accordingly, the [patent proprietor’s] submission that the evidential test or burden of proof for prior public use needs to be stricter than that for other grounds of objection under the EPC is rejected.

[…]

In T 472/92 (November 20, 1996) the same Board introduced a caveat with respect to this approach:

[3.1] Concerning the standard of proof that needs to be applied, the established legal practice of the Boards is to use the self-same standard of proof in prior public use objections as it does in others covered by A 100 : the balance of probability (see, e.g. T 270/90). In that case, the Board expressly refused to accept a submission that the much more rigorous standard of “beyond all reasonable doubt” should apply, even if, as was the case there, both parties were able to access and to adduce evidence relating to the decisive issue of confidentiality of the transactions alleged to constitute prior public use.

The Board reaffirms this approach, subject to the following caveat. Deciding any fact at issue by applying the above standard requires making a choice as to which one of the two contradictory propositions espoused by the parties is more likely to be true, since two contradictory propositions cannot, in logic and therefore in law, be either true or false. In judging the truth or falsity of either, regard must be had to the nature, content and likely source of the evidence that is available and can be adduced by the parties.

Generally speaking, in cases not involving the issue of prior public use, both parties are able to obtain and to adduce the evidence upon which their respective case rests. By contrast, in the majority of prior public use cases practically all the evidence in support of an alleged prior public use lies within the power and knowledge of the opponent, so the patentee seldom has any ready, or indeed any access to it at all. All he can, in practice, do is to challenge that evidence by pointing out any inconsistencies contained in it or to draw attention to any gaps in the chain of commercial transactions that needs to be established by the opponent in order to succeed on this ground.

In consequence, an opponent must prove his case up to the hilt, for little if any evidence will be available to the patentee to establish the contradictory proposition that no prior public use had taken place.

[…]

In February 2003, Board 3.5.01 issued decision T 55/01 where it found an exception to the exception:

[4.1] […] It is true that, in cases where only one party has access to information about an alleged public prior use, the case law has tended towards expecting that the public prior use be proved beyond any reasonable doubt (“up to the hilt”), answering the typical questions “What?”, “When?”, “Where?”, “How?” and “To whom?”, since the other party was reduced to merely pointing out inconsistencies or gaps in the chain of evidence; see T 472/92 [3.1]. The case law has however taken into account that cases of mass-produced consumer goods which are widely advertised and offered for sale to customers who often remain anonymous may require different treatment; see T 241/99 [4.2]. Indeed, to demand a complete chain of proof in such cases would make it unreasonably complicated for a party to successfully rely on a sale or an offer for sale to prove public availability. […]

I’ve had a look at T 241/99 (December 6, 2001; Board 3.5.2 ; in German). Here is my translation of the most relevant paragraphs:

[4.1] As correctly noted by opponent 02, according to the case law, one single proven sale is sufficient for making the sold object available to the public (T 482/89 [3]).

However, the Board is of the opinion that in such a case the requirements of R 55 c) [EPC 1973] would only be complied with if the name and the address of the single buyer were given within the time limit for filing an opposition. The Board does not see any difference between the indication “client X” and the absence of any indication with respect to the client.

[4.2] [Opponent] 02 insisted that the situation was to be assessed differently when there were sales to a plurality of clients, as in the present case. It is indisputable that sales on a market place or over the counter are to be assessed differently as regards the indication of facts and evidence than the case of a single sale; however, the Board is of the opinion that the present case does not belong to this kind of sale of bulk goods (Massenware) to anonymous clients. […]

If I understand things correctly, this obiter dictum from T 241/99 does not contradict T 472/92. It does not say that in a case where all the evidence in support of an alleged prior public use of bulk goods lies within the power and knowledge of the opponent, the balance of probabilities should be applied, but that the indication of facts and evidence should be assessed differently. When putting together T 472/92 and T 241/99, I would come to the conclusion that the standard of proof is still “up to the hilt” but that “up to the hilt” can mean something different when mass sales are considered. To be more precise, in order to establish beyond reasonable doubt that such a sale has taken place, you would not have to provide the names of the buyers, but other evidence as to the reality of the sale would do. Therefore, I am not sure that T 55/01 has really drawn the right conclusion from T 241/99.

Of course, there is much more case law out there and the doctrine of the Boards is not as clear-cut as might appear from this presentation. Your personal conclusions might also differ from mine. Be that as it may, I think these three decisions are well worth reading again.