Hoe tussentijdse generalisaties beoordelen voor toegevoegde onderwerpen

Case Law Octrooien

--Dit artikel is onderdeel van de EPO Case Law Newsletter en gaat verder in het Engels -- The Board in T1762/21 considered how ‘’intermediate generalizations’’ are assessed in respect of added subject matter. For assessing an intermediate generalisation in an amended claim for compliance with Article 123(2) EPC it has to be established whether, because of this generalisation, the subject-matter of the claim extends beyond what was, be it explicitly or implicitly, directly and unambiguously disclosed to the person skilled in the art using common general knowledge in the application as filed. This is the "gold" standard for assessing any amendment for its compliance with Article 123(2) EPC (G 2/10, point 4.3 of the Reasons). The Board found that features can be omitted from a claim if they are not necessary for achieving the technical effect of the claim.

Background

Decision T1762/21 concerns an appeal by an opponent against the opposition division’s, OD’s, decision to reject the opposition and maintain EP2352431 B1. The appellant (A) requested to revoke the patent, amongst others because in the claims as granted several features, essential for the system of claim 1, had been omitted from the claims when being amended. A argued that the claims contained an unallowable intermediate generalization and therefore violated the requirements of Art 123(2) EPC.

The patent

The patent relates to breast tomosynthesis systems, which can be used to acquire X-ray images of a breast at multiple angles in a single scan. The images are reconstructed into a series of slices that can be used to screen for early signs of breast cancer.

Claim 1 as originally filed related to an X-ray tube with an anode, a cathode, focusing cap and a controller. The port allows X-rays to pass through to define a static focal spot. The controller is coupled to at least one of the anode, the cathode, and focusing cup, and modifies at least one characteristic of the static focal spot during the exposure period. Claim 2 as filed in turn related to two options for the modification of the static focal spot: (i) the characteristic being a location of the static focal spot, or (ii) the characteristic being a size of the static focal spot.

During prosecution claim 1 was amended to option (i), to the tomosynthesis system comprising the X-ray tube as a whole and to how the controller controls the location of the static focal spot.

The Appeal

A found that claim 1 of the patent defined a system from which several essential features were omitted. For instance, features such as a scatter grid, “upper and lower” compression paddles, the anode being mounted on a shaft and rotated by a motor, a filter, and a collimator, would be lacking from claim 1 while being essential for the system according to claim 1. A referred to G1/93 and found that the claims contained an unallowed intermediate generalization and hence added subject matter. The respondent did not concur and argued that the application as filed related to a breast tomosynthesis system, and the alleged lacking features would not be inextricably linked to the function of the system and achieving the technical effect of the claimed invention.

Case Law

The Board set out that for the assessment of the allowability of an intermediate generalisation, it has to be established whether the claim presents technical information which extends beyond what was directly and unambiguously disclosed, be it explicitly or implicitly, to the person skilled in the art using common general knowledge in the application as filed.

The skilled person is presented with subject-matter extending beyond the application as filed when an amended claim includes only some features of an originally disclosed combination and the features left out of the claim were understood, by the person skilled in the art, to be inextricably linked to the claimed ones

Board of Appeal - European Patent Office

This is the "gold" standard for assessing compliance with Art 123(2) EPC (G 2/10, point 4.3 of the Reasons). G1/93, referred to by A, deals with the conflicting requirements of Art 123 EPC. It does however not prescribe special criteria for the assessment of intermediate generalizations. The Board further set out that ‘’The skilled person is presented with subject-matter extending beyond the application as filed when an amended claim includes only some features of an originally disclosed combination and the features left out of the claim were understood, by the person skilled in the art, to be inextricably linked to the claimed ones. This is the case if the skilled person would have regarded the omitted features to be necessary for achieving the effect associated with the added features. In such a situation, the amended claim conveys the technical teaching that the effect can be obtained with the claimed features alone, which is in contrast with, and extends beyond the originally disclosed subject-matter that the whole combination of features was needed. The passage in the Guidelines H-V.3.2.1 concerning intermediate generalisations has to be understood in this context.’’

Following on the latter reasoning the Board set out that “the features of the claims relate specifically to optimising the acquired images by acting on the focal spot. Features in the description concerned with other aspects of the system, such as the way the X-rays are generated or the way the breast is fixed in place on the detector, may be left out of the claims as long as they are not relevant to the optimisation, even if they contribute to the general functioning of the tomosynthesis system.”. The Board found that the skilled person would recognize that the omitted features do not contribute to the image optimization in the claimed system, and therefore came to the view that claim 1 did not contain added subject matter.