Friday, 3 June 2011

T 1414/08 – It’s 84 (Not 83)

I owe the knowledge of this decision to a kind colleague.

There is some disagreement between the Boards concerning the question of whether insufficiency of the disclosure of how to measure claimed parameters can result in insufficiency of disclosure within the meaning of A 83 (and A 100(b)) or not. T 1119/05 [3.2] has well summarised the situation:
As regards the inaccuracy of a parameter caused by the lack of indication of the exact measuring conditions it appears that the case law does not show such a clear direction. There is indeed case law which stresses that, in order to carry out the invention, the skilled person must be in a position to establish whether a product falls within the area covered by the claim and reliably to prepare the claimed product (T 256/87, T 387/01, T 252/02 and T 611/02). On the other hand, there is also case law which states that
“the lack of the indication of certain measuring conditions is not detrimental to the sufficiency of the disclosure but could raise a clarity problem with the consequence that the particular value must be interpreted in a broad manner …” (T 299/97 [1.2]).
This situation indicates that the relationship between A 83 and A 84 is not simple.
The present decision, dealing with the revocation of the opposed patent by the Opposition Division (OD), goes along the second path.

Claim 1 as granted had the following wording:
1. A soft, single ply-tissue product formed by conventional wet pressing of a cellulosic web, adhering said web to a Yankee dryer and creping the web from the Yankee dryer, said single-ply tissue including
(a) a temporary wet strength agent comprising an organic moiety, and
(b) nitrogenous softener agent,
and said single-ply tissue having a serpentine configuration, and low sidedness, a basic weight of at least total g/m2 pound 24.4 g/m2 (15 lbs/3000 sq. ft.) ream, a specific tensile strength of between 8.4 and 41.9 N/m per g/m2 (between 40 and 200 grams per three inches per pound per 3000 square foot) ream, a cross direction specific wet tensile strength of between 0.576 and 4.2 N/m per g/m2 (between 2.75 and 20 grams per three inches per pound per 3000 square foot) ream, the ratio of MD tensile to CD tensile of between 1.25 and 2.75, a specific geometric mean tensile stiffness of between 0.314 and 2.0 N/m/percent strain per g/m2 (between 0.5 and 3.2 grams per inch per percent strain per pound per 3000 square foot) ream, a friction deviation of less than 0.25, and a sidedness parameter of less than 0.3.
In its decision, the OD reasoned that due to the absence in the patent of any precise method of measurement for the claimed strength parameters, a skilled person would be unable both, to establish which tissue products fall under the scope of the claims and to reliably prepare the claimed product.

The Board does not agree.

[1] The gist of the [opponent’s] objection concerning lack of sufficiency consists in that an ambiguity with respect to the end values of the range for the dry and wet tensile strengths of the claimed tissue product arises from the fact that there exist different standard tests and different possibilities for carrying out those tests which all produce different results of measurement. Since the patent in suit did not disclose which specific method of measurement had to be applied, the ranges of tensile strength mentioned in the claims were undefined.

Apart from that, the standard methods did not use the sample size required in the patent in suit so that a skilled person would not use any of those methods.

As a result and contrary to the established Case Law of the Boards of Appeal as illustrated in T 611/02, a skilled person was unable both, to put the invention into effect across the whole scope of the claims and to determine whether he is working within the forbidden area of the claims or not. Hence, the patent in suit did not meet the fundamental requirements under A 83 or respectively A 100 b).

According to A 100 b) an opposition may be filed on the ground that a European patent does not disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. In other words, a European patent shall fulfil the same requirements as defined in A 83 for a European patent application.

[3] The Board observes that sufficiency of disclosure might be questionable if specific values of an unusual parameter are formulated in a patent as essential to the invention but no method of measuring that parameter is either known in the art or disclosed in the patent (Case Law of the Boards of Appeal of the EPO, 6th edition, 2010, chapter II.A.3.d), first paragraph).

[4] In the present case, the parameter in question is tensile strength, hence not unusual. Whilst being true that no specific method of measuring this parameter is disclosed in the patent in suit, there exist in the art several standardised test methods for determining the dry and wet tensile properties of paper and paperboard including tensile strength. There is no doubt that variations in the test conditions, e.g. the sample size, the jaw speed or elongation speed, have an influence on the result of the measurement. However, as it is known from the standard methods that deviations from the specified conditions are possible, in particular deviations in sample size and jaw speed (e.g. document D6 [… and] D9 […]), a skilled person had no reasons not to use any of those well-known test methods.

Hence, the problem to be considered here boils down to the fact that, depending on the method of measurement, there exists an uncertainty as to the actual end values of the range for the tensile strength mentioned in the independent claims.

This problem remains the same, however, even if a specific method of measurement was disclosed in the description since the claims would not be restricted to that method.

[5] The [opponent] pointed to the second sentence of A 69(1) by arguing that the description should be used to interpret the claims.

A 69(1) relates to the extent of protection conferred by a European patent of patent application. According to the Protocol on the Interpretation of A 69 which was adopted as an integral part of the EPC to provide a mechanism for harmonisation of the various national approaches to the interpretation and determination of the protection conferred by a patent, this should be done so as not to overestimate either the literal wording of the claims or the general inventive concept disclosed in the description (see also G 2/88 [2.1,3.3,4]).

[6] However, this does not mean, that the scope of protection conferred by a claim is limited by the description.

In decision G 2/88, the Enlarged Board of Appeal was concerned with questions relating to A 123(3) with respect to a change in category from a claim for a physical entity to a claim for a second non-medical use. The Board took the view that upon proper interpretation within the terms of A 69 such a use claim would implicitly contain a functional feature as a technical feature (reasons [9]).

It was held that the use claim which was in effect a claim to a physical entity only when it is used in the course of the particular physical activity (of the use) conferred less protection than a claim to a physical entity per se which conferred absolute protection upon such physical entity, no matter where it exists and what is its context (reasons [5]).

[7] Transferred to the present case, where a tissue product is claimed and different methods of measuring the tensile strength of that product are known in the art which give different results, this means that the end values of the range for the tensile strength remain ambiguous, irrespective of whether a specific test method is disclosed in the patent or not.

In other words, if - for the purpose of sufficiency of disclosure - it was a requirement that a person skilled in the art must know the scope of the claims, the disclosure of the claimed subject-matter would be insufficient except where a complete method was included in the claim.

[8] The Board notes that the scope of protection as defined in A 69 may have some relevance for the purposes of A 84 and A 123(3) which both mention the protection sought for or conferred by a patent. In contrast, A 83 concerning sufficiency of disclosure is completely silent about that issue.

For these reasons, the Board takes the view that under the present circumstances the question of whether a skilled person can know what is covered by the claims is a question of definition of the claimed subject-matter, hence A 84, rather than of sufficiency of disclosure (A 83).

[9] The Board further observes that the question of whether a skilled person is able to carry out the invention within the full scope of the claims is based on an assumption that their scope might extend to undisclosed variants. However, such doubts have to be substantiated by verifiable facts (see also e.g. T 1886/06 [1.4.2]).

No evidence in this respect has been presented by the [opponent]. On the contrary, it has been shown by way of the [opponent’s] experiments Dl9 that there exists a correlation between the measured tensile strength value and the jaw speed which can be varied within wide limits and adapted according to circumstances.

[10] Hence, the Board is of the opinion that the ambiguity of the end values of the ranges concerning tensile strength of the presently claimed tissue product is not a matter to be addressed under A 83 but a question of A 84 which requires that the claims shall define the matter for which protection is sought and be clear and concise as well as supported by the description. Due to the thus reduced significance of the values, this means that in opposition and appeal proceedings more prior art may be considered for the assessment of novelty and inventive step, namely that concerning tissue products which when measured in a technically reasonable way according to any of the known test methods give strength values within the claimed range.

[11] Concerning sufficiency of disclosure, the Board observes that a skilled person is not only in a position to measure the strength of the tissue product but also that the patent contains the information required for producing that product […]. The latter has not been contested by the [opponent].

The Board, therefore, concludes that the patent satisfies the requirements of A 100(b).


[12] The patent was revoked on the grounds of A 100(b). Whether the patent meets the other requirements of the EPC, in particular those of A 54(1) (2) and A 56, has not yet been established.

Since it is the function of appeal proceedings to give a judicial decision upon the correctness of a separate earlier decision taken by a first-instance department (Case Law of the Boards of Appeal, 6th ed. 2010, VII.E.l), the Board finds it appropriate to make use of its power under A 111(1) and remits the case to the first instance for further prosecution, thereby allowing the respective request of both parties.

To download the whole decision or to have a look at the file wrapper, click here.