T 0030/01 29-06-2004

1. The appeal complies with the requirements mentioned in Rule 65(1) EPC and is therefore admissible.

2. Main request: Priority - State of the art

The respondent has contested the opposition division's view that the invention according to the patent is entitled to priority from US application 692877 of 29. April 1991 and submitted that document E4 published in November 1991, i.e. after the priority date but before the date of filing 29 April 1992 of the patent, constitutes prior art within the meaning of Article 54(2) EPC. In view of the further submission of the respondent that the content of document E4 is highly relevant for the assessment of patentability, and since in the Board's view the content of the document would appear to be even closer to the claimed subject-matter than any of the documents relied upon by the opposition division for the assessment of novelty and inventive step, the question arises whether the Board is in a position to endorse the assessment of entitlement to priority made by the opposition division and confirm the negative finding of the opposition division relating to the status as prior art of document E4. This question is to be considered in the light of the principles laid down in opinion G 2/98 (OJ EPO 2001, 413) of the Enlarged Board of Appeal.

2.1. Claim 1 - Entitlement to priority

Claim 1 of the main request is directed to an apparatus for interferometrically imaging the internal structure of a sample, the apparatus comprising, among others, a probe module. The question of whether the invention defined in claim 1 is entitled to the claimed priority under Articles 87(1) and 88 EPC depends on whether claim 1 and the priority document concern "the same invention", i.e. whether the skilled person can derive the claimed subject-matter, and in particular - as disputed by the respondent - the features relating to the probe module, directly and unambiguously, using common general knowledge, from the priority document as a whole, see in this respect G 2/98 (supra), "Conclusion" together with point 9 of the reasons.

2.1.1. The main line of argument advanced by the appellant in support of the entitlement to priority of the features relating to the probe module defined in claim 1 relies on claim 30 and on the paragraphs bridging pages 8 and 9, and pages 38 and 39 of the priority document.

According to the paragraph bridging pages 38 and 39 of the priority document, in the previous passages "the beam has been projected only along a single axis. However, by using a probe beam steering mechanism in the sample arm, the probe and/or beam may [...] be laterally scanned on a sample area of interest". The reference in this passage to a "beam steering mechanism" for laterally scanning the probe and/or beam as opposed to projecting the light beam "only along a single axis" supports the provision of "means for scanning the sample by steering the direction of light propagation applied to the sample" as defined in claim 1 according to the appellant's main request. However, while present claim 1 specifies that the probe module is "arranged in [the] measuring beam path at its terminating portion, which probe module comprises" the light steering means and therefore requires the light steering means to be provided in the probe module at the terminal portion of the measuring beam path, the priority document specifies the provision of the probe at the terminal portion of the sample arm (see paragraph bridging pages 8 and 9, and claim 30), i.e. of the measuring beam path according to the terminology of claim 1, but only refers to "probe beam steering mechanism in the sample arm" [emphasis added] (last paragraph of page 38), i.e. in the measuring beam path, and therefore fails to specifically disclose the provision of the light steering means in the probe. In addition, the reference in this paragraph to the "probe and/or beam" being "laterally scanned on a sample area of interest" does not necessarily imply that the probe beam steering mechanism is arranged in the probe itself or, as contended by the appellant, that the probe is being scanningly moved so as to steer the direction of propagation of the light beam; in particular, none of the passages of the priority document excludes construing the scanning operation of the probe in the sense that the light beam is scanned over the probe and then over the sample, i.e. in the sense that the direction of the light beam incident on and transmitted by the probe towards the sample is being steered by means located in the measuring beam path optically upstream of the probe so as to scan the light beam over the probe and then over the sample.

As regards the paragraph bridging pages 8 and 9 of the priority document, this paragraph only states that the probe "may be scanned to obtain two or three dimensional measurements" and is silent as to the provision of light steering means and the location of these means relative to the probe. In addition, as already discussed above, the indication that the probe "may be scanned" does not point unambiguously to the probe - or elements of the probe - being moved so as to steer the direction of propagation of the light beam.

The appellant has also referred to claim 30 of the priority document, the claim defining "a system [...] wherein said second optical path terminates in a probe for applying a beam of said radiation to said sample, and including means for scanning said beam in transverse direction over said sample [...]". It is, however, unclear in the formulation of the claim whether the grammatical subject of the participle "including" is the system or the probe. Consequently, even if it were assumed for the sake of argument that the means for scanning defined in the claim correspond to light steering means as disclosed in the paragraph bridging pages 38 and 39 of the description, the formulation of the claim would not allow the unequivocal conclusion that the light steering means are provided in the probe, all the more so as this specific construction of the claim would then not appear to be supported by the description of the priority document as discussed above.

2.1.2. According to an alternative line of argument advanced by the appellant, even assuming that the priority document, and in particular claim 30, is not unambiguously clear as to whether the light steering means are provided or not in the probe, nonetheless the skilled person would, though possibly not immediately, at least directly and unambiguously derive the provision of the light steering means in the probe from the implicit disclosure of the priority document, i.e. as one of the two possible alternative implementations of the teaching of the document. This line of argument, however, also fails to convince the Board. As already noted above, the description of the priority document unmistakeably indicates the provision of the light steering means "in the sample arm" (page 38, last paragraph) and, in the absence of any other express disclosure pointing to other alternative arrangements, this precise disclosure deprives of support the appellant's construction of the disclosure of the priority document, and in particular of claim 30, as implicitly disclosing the provision of the light steering means in and outside the probe as two complementary alternative implementations of the disclosure of the document - let alone as disclosing any specific one of these two alternatives by way of "implicit disclosure" by reference to the common general knowledge, see in this respect decisions T 823/96 (point 4.5 of the reasons), T 744/99 (point 4.5 of the reasons), and T 818/00 (point 1.1 of the reasons), none of them published in OJ EPO.

The further contention of the appellant that the derivability from the priority document of the provision of light steering means in the probe is in line with the so-called "novelty test", in particular in view of the German jurisprudence and doctrine on novelty, cannot be followed either. In the absence of any express or implied disclosure in the priority document of the provision of light steering means in the probe, the appellant's contention is manifestly at variance with the case law developed by the Boards of Appeal in this respect and according to which a specific embodiment encompassed by, and falling within the terms of a generic disclosure is, in the absence of any explicit or implicit disclosure of the specific embodiment, generally acknowledged as being novel over the generic disclosure, even when the implementation of the latter only leaves open the choice between two alternative embodiments (see for instance decision T 651/91, not published in OJ EPO, point 4.3 of the reasons). Furthermore, and for the same reasons, the appellant's contention is also at variance with the criterion consistently applied by the Boards of Appeal that a generic disclosure implicitly encompassing two or more alternative embodiments can generally not give rise to a right of priority in respect of a specific one of the embodiments that is neither explicitly nor implicitly disclosed (see for instance decision T 61/85, not published in OJ EPO, point 10 of the reasons), the latter criterion being a particular form of the "disclosure test" laid down in G 2/98 and constituting the logical corollary of the case law mentioned above and the established principle - confirmed in opinion G 2/98, supra, points 8.1 and 8.4, see also T 744/99, supra, points 4.3 to 4.5 of the reasons - that no right to priority can be acknowledged for an invention that is regarded as novel over the disclosure of the corresponding priority document.

2.1.3. The Board concludes that the provision of light steering means in a probe module at the terminating portion of the measuring beam path as defined in claim 1 is neither directly nor unambiguously derivable from the priority document within the meaning of G 2/98. Accordingly, the priority document and the subject-matter of claim 1 do not concern the "same invention" as required by Article 87(1) EPC and consequently the invention defined in claim 1 of the main request is not entitled to priority under Articles 87(1) and 88. EPC.

2.2. Independent claim 7 - Entitlement to priority

Independent claim 7 is also directed to an apparatus for interferometrically imaging the internal structure of a sample comprising a probe module, the claim reciting the same features of the probe module of claim 1 referred to in point 2.1 above. Consequently, the invention defined in claim 7 is not entitled to priority either (Articles 87(1) and 88 EPC) for the same reasons put forward in point 2.1 above with regard to claim 1. Moreover, the non-entitlement to priority of claim 7 was not disputed by the appellant during the proceedings in view of the additional features incorporated by way of amendment into the claim and relating to the provision of a frequency modulated, spectrally coherent optical radiation source for which no counterpart is disclosed in the priority document.

2.3. Status of document E4 as prior art

As the subject matter defined in independent claims 1 and 7 of the main request is not entitled to the claimed priority and document E4 has been published before the date of filing of the patent, the Board concludes that the disclosure of document E4 constitutes prior art within the meaning of Article 54(2) EPC in respect of the appellant's main request.

3. Further prosecution

Each of independent claims 1 and 7 according to the main request results from substantial amendments made to granted claim 1 on which the contested decision is based, and these amendments affect the whole basis on which the decision under appeal was made.

Furthermore, the Board finds - without giving detailed reasons that might risk prejudicing the assessment of the case by the opposition division in the subsequent prosecution of the case as ordered below - that the disclosure of document E4 appears to be of significant relevance for the assessment of the patentability of the subject-matter now claimed and - as already set out in point 2 above - the document even appears to be closer to the invention than any of the documents relied upon by the opposition division in its decision. In addition, although document E7 was already considered during the first-instance proceedings, the inclusion in amended claim 7 of a frequency modulated, spectrally coherent optical radiation source calls for a reassessment of the content of document E7 in view of the measures taught in the passage at lines 34 to 50 on page 2 and in claims 4 and 13 and which were not addressed during the first-instance proceedings.

All these circumstances substantially alter the factual framework of the case under appeal compared with that upon which the contested decision had been based and therefore results in the Board being presented with a fresh case requiring further examination in relation to both the formal and substantive requirements of the EPC. In addition, it is current practice that any fresh assessment of a case should normally be carried out by the first instance so that the parties are not deprived of the possibility of a subsequent review.

In view of the foregoing, the Board considers it appropriate in the circumstances of the case to make use of its discretionary powers under Article 111(1) EPC and to remit the case to the opposition division for further prosecution on the basis of the amended claims according to the appellant's requests, it being noted that during the oral proceedings the appellant has given its express agreement with this course of action and that the respondent did not avail itself of the opportunity to comment on the Board's provisional position previously communicated to the parties that the case could possibly be remitted for further prosecution (see points IV to VI above).

In addressing the remitted case, it will be necessary for the opposition division to consider not only the substantive merits of the case in the light of documents E4 and E7 and the remaining prior art on file, but also the formal admissibility of the amended claims according to the present requests of the appellant, and in particular the compliance of the amendments with the formal requirements of the EPC (Article 102(3) together with Articles 84 and 123(2,3) EPC) and - if deemed necessary - the admissibility under Rule 57a EPC of the amendments to the dependent claims. The opposition division would also have to consider whether to admit (Article 114(1) EPC) or disregard (Article 114(2) EPC) the observations presented during the appeal proceedings by the third party (Article 115(1) EPC) and partially incorporated by reference in the respondent's own case (see point III above).