8. Skilled person
8.2. Related technical fields (neighbouring fields)
Two landmark decisions, T 176/84 (OJ 1986, 50) and T 195/84 (OJ 1986, 121) addressed in detail the problem of the relevant technical field, i.e. the question of the extent to which neighbouring areas beyond the specific field of the application might be taken into consideration when assessing inventive step. According to T 176/84 the state of the art to be considered when examining for inventive step includes, as well as that in the specific field of the application, the state of any relevant art in neighbouring fields and/or a broader general field of which the specific field is part, that is to say any field in which the same problem or one similar to it arises and of which the person skilled in the art of the specific field must be expected to be aware. The board in T 195/84 added that the state of the art to be considered included that in a non-specific (general) field dealing with the solution of any general technical problem which the application sought to solve in its specific field. Such solutions of general technical problems in non-specific (general) fields had to be considered as forming part of the general technical knowledge which a priori was to be attributed to those skilled persons versed in any specific technical field. These principles have been applied in a large number of decisions.
In T 560/89 (OJ 1992, 725) the board took the view that the skilled person would also draw on prior art in other fields which were neither neighbouring nor broader general fields, if prompted to do so because the materials used were related or because of public debate about a technical problem common to both fields. Expanding on this, T 955/90 added that, in practice, the person skilled in a broader general field would also draw on the narrower, more specialised field of the known main application of the general technology in search of a solution to a problem lying outside the special application of that technology (T 379/96).
In T 454/87 the board expressed the opinion that a skilled person specialising in a particular technical field (gas chromatography equipment) would, in the course of their normal professional activity, also observe developments in equipment used in a related technical field (absorption spectral analysis).
In T 891/91 the board stated that a skilled person in the field of lenses for ophthalmic use, confronted with the technical problem of adhesion and abrasion resistance of a coating made on a surface of the lens, would also refer to the state of the art in the more general field of coated plastic sheets in which the same problems of adhesion and abrasion resistance of the coating arose and of which they was aware.
In T 1910/11 the board stated that, whether the prior art and the claimed invention belonged to neighbouring technical fields within the meaning of T 176/84 was less a question of whether the relevant implementation parameters were identical than a question of the degree of similarity between the respective problems, boundary conditions and functional concepts. Applying this to the case in hand, it observed that automotive electronics and avionics were traditionally considered to be neighbouring technical fields because they involved similar problems (e.g. interference resistance, robustness and reliability), boundary conditions (e.g. mobility) and functional concepts (e.g. physical/logical separation of the communications systems for safety and maintenance data in the vehicle).
In T 767/89, regarding carpets, the board ruled that wigs were neither a neighbouring technical field nor a broader general one which included the former field. So wigs were not a related technical field in which the person skilled in carpets would have been prompted to seek solutions. The two inventions addressed different problems; the user requirements were not comparable.
In T 675/92 the board held that, because of the differing security risks, a skilled person could not be expected to search in the field of bulk-goods packaging for ideas for the design of a closure for a means of conveying money.
Further comments on the concept of relevant field are to be found in several other decisions, including the following: T 277/90 (in dentistry, moulding technology and prosthodontics are neighbouring technical fields), T 358/90 (discharging the content of a portable toilet did not lead the skilled person to the field of filling a tank of a chain saw by means of a special kind of container), T 1037/92 (a person skilled in the art of making fuse links for programmable ROMs would also have consulted the documentation in the field of ultraminiaturised integrated switches), T 838/95 (the pharmaceutical and cosmetic fields were immediate neighbours), T 26/98 (the board did not consider the field of electrochemical generators to be a neighbouring field of iontophoresis because, though both fields relied on electrochemical processes, such processes had substantially different purposes and applications and, consequently, had to satisfy different requirements), T 1202/02 (the manufacture of mineral fibres and that of glass fibres were two closely related technical fields irrespective of differences between the raw materials respectively used), T 47/91 (casting rolls and casting wheels when continuously casting molten metal represent neighbouring technical fields).
In T 244/91 the board found the person skilled in the art of heat exchangers would take account of publication D3 on "gaskets of plate heat exchangers", or would at least consult a specialist in the non-specific field of gaskets who must be expected to be familiar with such standard literature.
In T 1154/16 the board found that the disclosures of D9 and D19 in the case in hand could not be considered to be in a neighbouring field to that of shoe press belts for papermaking, but that they did form part of a broader, general field, relating to the general use of polyurethanes in dynamic mechanical applications solving similar problems to the current case. Therefore the skilled person would consider the disclosure of both documents.
In T 1979/18 the board found that while it was true that agricultural engineering may combine (depending on the particular application) with a wide variety of other disciplines such as civil, chemical, mechanical, bio-systems, and environmental engineering, this did not mean that the skilled person was therefore also fully knowledgeable in those fields.
In T 28/87 (OJ 1989, 383) the board held that if reference was made in the introduction to the description of an application or a patent to a state of the art which could not objectively be classified as a relevant field, that state of the art could not in the course of examination for patentability be applied to the applicant's or patent proprietor's disadvantage as a neighbouring field merely on account of that reference.
In T 1731/20 the board found that motor vehicle engines was not a neighbouring technical field of food processing machinery because the latter was undisputedly powered by electric or pneumatic motors while motor vehicles were powered by combustion engines. Further, a single technical book within the narrow technical area of vehicle electronics was not adequate proof that reducing the range of combustion motors to just one motor used with various data records was a general solution to a general technical problem. The board added that a skilled person who used a specific device such as a motor vehicle in an everyday way did not possess extensive knowledge in this area by virtue of such use. Their knowledge was that of an average user of motor vehicles, familiar with the general workings and structure of motor vehicles but unfamiliar with production or marketing aspects of the combustion engine variants used. The board therefore made a distinction between the case at hand and decisions T 560/89, T 176/84 and T 195/84.
In T 1787/20 the board was not convinced that the area in question was the area of cartridges. There was no distinct technical area covering every possible type of cartridge because cartridges were used for all kinds of applications. They were used, for example, for ammunition, toner and flammable gas, although the cartridge sizes, material and requirements differed for each of these examples. In the board’s view, the skilled person was given no indication in the case at hand to look for the solution in a technical area other than the area of water-guiding household devices, making that the area in which the person was to be regarded as being skilled. See also parallel proceedings T 1797/20.
- T 1632/22
In T 1632/22, In ex parte case T 1632/22, the application related to liveness detection in relation to authentication, e.g. when unlocking a phone based on a face image. The application proposed to categorise the images as a function of their "quality" and to use different liveness detectors for each quality type. The examining division concluded there was a lack of inventive step over D1 (face authentication).
With an amendment in substance to define the quality parameter used to define the quality type, the new feature of claim 1 was not disclosed in D1. The board saw only two differences between claim 1 and D1 which might support the presence of an inventive step, namely that the claimed method was used for liveness detection and that it considered also quality parameters other than those disclosed for the "specialized classifiers" of D1. For the appellant, D1 did not qualify as the closest prior art as it was concerned with authentication rather than with liveness detection.
In the board’s view, the novelty requirement provides that no patent can be granted for anything that is already known. The inventive step requirement raises the bar to a patent by also excluding matter which is obvious over what is known. That which is obvious to the skilled person cannot depend on anything that the skilled person does not know yet. In particular, what is obvious at the filing date of a patent application cannot depend on the content of that patent application. Conversely, an argument that a skilled person having regard to some piece of prior art will find something to be obvious cannot be rebutted on the basis of what the application says. In particular, the application cannot be invoked to limit the prior art under consideration or the expertise of the skilled person (their "art") on the basis of the stated "field of the invention". That essentially any piece of prior art can be considered in an inventive step analysis has been stated several times in the case law. The definite articles in the phrase "the person skilled in the art" in Art. 56 EPC are not meant to limit the relevant "arts". Any successful rebuttal of an inventive step objection must address the obviousness argument directly, without reference to the application.
It is a matter of efficiency when assessing inventive step to consider only persons skilled in arts related to the claimed invention, and, consequently, only prior art which such a person may have regard to. The board considered that a person skilled in some art may well have regard to prior art from a field which is not, in a narrow sense, their "own field". It is reasonable to assume, for instance, that persons skilled in one field will typically keep themselves informed about developments in related fields, and in this sense have regard to prior art in related fields. The board disagreed with T 646/22 and held that in principle, all problems which the skilled person would have addressed (or been asked to address) based on the prior art alone are valid ones. In the present case, the board assumed a person skilled in liveness detection methods. Such a person was, generally, interested in improving, or finding alternatives to, known liveness detection methods, based on the knowledge that known methods have known pitfalls. Liveness detection for authentication and authentication were closely related technical areas. The board noted that it was typical to try adapting developments in neighbouring fields to the own area of interest. It was certainly common practice in image processing, in particular when the images were of the same type. Thus, in the board's judgement, the person skilled in the art in liveness detection would have regard to D1 and would have reason to adapt its solution to liveness detection in a way leading to the invention according to claim 1 of the main request before the examining division. The current requests differed from that request ("quality parameter").
Finally, the board noted that during examination a relatively large number of documents were cited, some of them concerned with liveness detection, but were not discussed in the decision. A positive decision on inventive step could not be issued before at least these documents have been discussed (Remittal).