T 1026/10 – Decay

Another telling example of how not to draft applications ...

Claim 1 of the fourth auxiliary request before the Board read (in English translation):

Security document comprising a composition capable of anti-Stokes fluorescence as a security feature, wherein the composition comprises a gadolinium oxysulfide matrix material made from a composition of the formula (Gd_(1-x-y))₂O₂S:Yb_xTm_y, wherein

• x and y fulfil the requirements: 0.20 ≤ x ≤ 0.60 and 0.0001 ≤ y ≤ 0.05;
• Ytterbium (Yb) acts as absorbing ion, for absorbing electromagnetic radiation; 
• Thulium (Tm) acts as an emitting ion, for emitting electromagnetic radiation the wavelength of which is shorter than the wavelength of the absorbed radiation (anti-Stokes luminescence);
• the concentrations of the absorbing and emitting ions are chosen such that proportionate quenching of the anti-Stokes luminescence is achieved (concentration quenching), in order to ensure that the increase and decrease times are sufficiently low as to be suitable for high-speed detection with read-out speeds between 3 and 6 m/s.

This claim was found to be unclear:

*** Translation of the German original ***

[3] Claim 1 of the fourth auxiliary request is directed at a security document comprising the anti-Stokes fluorescence composition (Gd_(1-x-y))₂O₂S:Yb_xTm_y as a security feature, wherein x and y, i.e. the concentrations of the absorbing and emitting ions, are chosen within the domains 0.20 ≤ x ≤ 0.60 and 0.0001 ≤ y ≤ 0.05 “such that proportionate quenching of the anti-Stokes luminescence is achieved (concentration quenching), in order to ensure that the increase and decrease times are sufficiently low as to be suitable for high-speed detection with read-out speeds between 3 and 6 m/s”.

[3.1] A 84 in connection with R 43(1) establishes the requirement that the claims have to be clear and define the matter for which protection is sought in terms of the technical features of the invention. This requirement ensures that the public is not left in any doubt as to which subject-matter is covered by a particular patent and which is not. The Board is of the opinion that it follows from this principle of legal certainty that claims are not to be considered clear within the meaning of A 84 if they do not allow to draw that distinction (see T 337/95 [2.2-5]). However, claims comprising an unclear technical feature generate doubts as to what is precisely encompassed by the subject-matter of the claims. Because of this lack of legal certainty such claims are not clear within the meaning of A 84.

[3.2] In the present case the fluorescent material is partly defined by means of the result to be obtained: x and y have to be chosen within certain domains such that

(a)    such that proportionate quenching of the anti-Stokes luminescence is achieved, in order to

(b)   ensure that the increase and decrease times are sufficiently low

(c)    as to be suitable for high-speed detection with read-out speeds between 3 and 6 m/s.

Thus x and y – and, therefore, the fluorescent material itself – are defined by a cascade of inter-dependent parameters.

[3.3] The upper limits for the increase and/or decrease times that have to be guaranteed according to (b) are not made unambiguous by the indication that they have to be “low”, because the expression “low” is a relative one and does not have an unambiguous reference point in the filed of fluorescent materials (see T 337/95 [2.8]). Moreover, the description of the application under consideration does not give any values for suitable increase and decrease times, let alone a possible upper limit.

[3.4] Said increase and decrease times mentioned in claim 1 are, however, further defined by the requirement that they have to allow for high-speed detection with read-out speeds between 3 and 6 m/s.

[3.5] The unambiguous characterisation of a product in a claim by means of a parameter requires the parameter to be clearly and reliably determinable. Therefore, the knowledge of the method and the conditions for determining the parameter is required for the parameter to be unambiguously defined (see T 412/02 [5.8-9]). In order for the subject-matter for which protection is sought to be well defined, the claim as such has to disclose to the skilled person reading it how the parameter is to be determined. In principle, this means that the method of determination and the measurement conditions that could have an influence of the value of the parameter have to be indicated in the claim, either explicitly or, where absolutely necessary, by means of references to the description pursuant to R 43(6). Such an indication is superfluous only if it can be shown that the skilled person would immediately know which method and which conditions are to be applied.

[3.6] In the present case the concentrations of x and y are to be chosen such that the resulting fluorescent material can be detected at “high-speed”, i.e. with read-out speeds between 3 and 6 m/s. Neither the claim nor the description of the original application discloses how the detection is to be performed. Thus the skilled person does not know precisely what is to be measured, nor which measurement method is to be used, under which conditions and with which device, respectively, let alone which measurement value would be considered to be “detectable” at all. Moreover, the application under consideration does not contain any example for a claimed fluorescent material, i.e. it does not mention any concrete values for x and y.

[3.7] Consequently, as neither the method of determination nor the measurement conditions that could have an influence on the detectability of the fluorescent material by means of “high-speed detection” are indicated in the claim or in the description, it is not possible to unambiguously characterise the claimed fluorescent material by means of x and y values.

[3.8] The appellants pointed out that the skilled person knew which method and which conditions were to be used, i.e. the high-speed methods that are commonly used for checking security documents. Those methods used the detectors that are customary in this industry.

However, it is undisputed that there are several high-speed detection methods and that different parameters/conditions have an influence on the “detectability”. Thus, whether a given fluorescent material is considered to be detectable or not inter alia depends on whether the luminescence that is to be measured is in the visible or in the invisible range […], what the size of the security feature is, how much fluorescent material is used in the security feature, as well as on the properties of the printing ink into which the fluorescent material is incorporated. Moreover, it is undisputed that the skilled person can use different detectors. Whether a given fluorescent material is considered to be detectable or not also depends from the detection threshold […] and the power of the exciting light, etc. Moreover, [the application] does not give any lower limit for what is considered to be detectable.

[3.9] The appellants argued, on the basis of graph D14 […] that at a given constant concentration of Thallium (y) the skilled person could determine suitable limits for the Ytterbium concentration (x). In graph D14 the working domain suitable for high-speed detection for a fluorescent material having a y value of 0.0007 was indicated by means of a yellow surface.

However, the expression “high-speed detection” still remains undefined. It is not clear why of all things those specific limits for the increase and decrease times allow for high-speed detection. Thus the chosen boundaries for the working domain are purely arbitrary.

[3.10] As for the reasons given above the technical feature “the concentrations of the absorbing and emitting ions are chosen such that proportionate quenching of the anti-Stokes luminescence is achieved (concentration quenching), in order to ensure that the increase and decrease times are sufficiently low as to be suitable for high-speed detection with read-out speeds between 3 and 6 m/s” is unclear and the skilled person is not enabled to determine its precise meaning, this expression generates a lack of clarity as to what exactly is encompassed by the subject-matter for which protection is sought, and what is not. Thus claim 1 of auxiliary request 4 does not comply with the requirement of clarity pursuant to A 84.

[3.11] As the subject-matter of claim 1 of auxiliary request 4 is the most narrow and as the wording of the contested feature […] is more precise than in the other requests (for instance, in the main request and in auxiliary requests 1 and 3 “high-speed detection” is not defined via a concrete read-out speed, and the main request does not give any quantitative values for x and y […]), the main request and auxiliary requests 1 to 3 share the fate of auxiliary request 4.

[3.12] Thus all of the requests of the appellants violate A 84 and, therefore, cannot be allowed.

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