UK: Inventive Step In The USA, The UK and in Europe

Last Updated: 28 October 2002
Article by Paul Cole

"… and in every age there come forth things that are new and have no foretelling, for they do not proceed from the past."1


What is an invention? We need to know, or we have no basis for discerning invention in any set of facts placed before us. But the EPC does not define "invention" in any its 178 Articles, the reason being that the contracting states were unable to agree on such a definition2. Our colleagues in other jurisdictions are under a similar handicap. Fortunately the EPO Appeal Boards have filled the gap. They have devised a test for inventive step that is easy to apply, gives consistent and widely accepted results, and is arguably better than any comparable test used anywhere else in the World.

With hindsight it is not surprising that this should have happened. When the EPO was established the members of the Boards of Appeal were drawn from senior practitioners from all the contracting states, and the jurisprudence of the Appeal Boards has resulted from a fusion of their national traditions and ideas.

The EPO approach to problem/solution analysis which as will be explained below is effect-based is not identical to the Germanic approach which involved (a) ascertaining the problem to be solved, (b) selecting the technical principle to be applied, and (c) selecting particular means to solve the problem, unobviousness in any of the above stages supporting inventive step3. Problem/solution analysis was an ingredient of German law, just as it could be found in U.K. law but this author has been unable to find evidence that it was so dominant a test for determining patentability as it is under the EPC. There were other important concepts of German law that have not been expressly carried forward into the EPC or the jurisprudence of the EPO Appeal Boards, such as erfindungshöche and technical advance. About the time when the EPO opened, the contemporary writings of our German colleagues do not show a sustained effort directed at convincing practitioners in the UK and that problem/solution analysis should be made into the dominant feature of the test for inventive step to be applied by the EPO. Instead they were drawing attention to the disappearing German concept of technical advance4. The author recalls from discussions with George Szabo who was one of the founder members of the EPO Appeal Boards that the technical problem test evolved immediately after the EPO was established as a result of intensive discussions and studies carried out by the newly appointed members of the Appeal Boards in preparation for the expected flow of appeal cases, that they were determined to take advantage of the best features of all their national traditions, and that it is misleading to ascribe the features of the EPO approach to the traditions of any one country.

Is it positive or negative characteristics that matter?

The EPC, like the UK Patents Act 1949 and like 35 USC bolts together concepts of inventiveness and obviousness that are not synonymous. Art. 52(1) EPC requires an invention to involve an inventive step. Article 56 explains that an invention should be considered as involving an inventive step if it is not obvious to a person skilled in the art. But if "inventive step" makes no significant addition to the Convention, why did not Art. 52(1) simply specify un-obviousness as its third criterion?

"Invention" comes from the Latin verb invenire meaning to find or to come upon. On that basis, the Convention requires an invention to have the positive attribute of an underlying discovery by the inventor. That requirement fits the structure of patent claims, which specify a set of integers, relationships between the integers and a function or result that flows from providing those integers and establishing those relationships. The new function or result, if unexpected, provides the required positive attribute and can be identified with the invenium or finding upon which the concept of "invention" is based. That formulation is consistent with the expectations of most scientists and engineers who it is submitted expect a patentee to have achieved something positive before he can apply for a patent. It is also consistent with the views of those who drafted the US Constitution, who were working in the common law tradition and in the light of some 160 years experience since the passing of the Statute of Monopolies5. They included in the Constitution a provision authorizing Congress "To promote the progress of useful arts by securing for limited times to inventors the exclusive right to their discoveries."

Before the introduction of obviousness as a statutory requirement into UK6 and US7 law, the courts focused on the requirement of inventiveness, and older UK and US decisions should be read with this in mind. For example, in the U.K. the courts held that a scintilla of invention was needed to support the subject matter of a claim8. In the USA, the Supreme Court held that patentability required the involvement of more ingenuity than the work of a mechanic skilled in the art9 and in 1941 controversially went on to say that an invention should reveal the flash of creative genius10. On this formulation, the skilled person implicitly has a degree of creative power. In the European view the skilled man does not display ingenuity, is cautious in modifying or adjusting a known product or process but would make appropriate changes that appeared to be easy and to involve no obvious risks11. Laddie J. has further described him in his decision in Pfizer v Lilly Icos12 in the following memorable passage:

"The question of obviousness has to be assessed through the eyes of the skilled but non-inventive man in the art. This is not a real person. He is a legal creation. He is supposed to offer an objective test of whether a particular development can be protected by a patent. He is deemed to have looked at and read publicly available documents and to know of public uses in the prior art. He understands all languages and dialects. He never misses the obvious nor stumbles on the inventive. He has no private idiosyncratic preferences or dislikes. He never thinks laterally. He differs from all real people in one or more of these characteristics. A real worker in the field may never look at a piece of prior art for example he may never look at the contents of a particular public library or he may be put off because it is in a language he does not know. But the notional addressee is taken to have done so. This is a reflection of part of the policy underlying the law of obviousness. Anything which is obvious over what is available to the public cannot subsequently be the subject of valid patent protection even if, in practice, few would have bothered looking through the prior art or would have found the particular items relied on. Patents are not granted for the discovery and wider dissemination of public material and what is obvious over it, but only for making new inventions. A worker who finds, is given or stumbles upon any piece of public prior art must realize that that art and anything obvious over it cannot be monopolized by him and he is reassured that it cannot be monopolized by anyone else."

Obviousness come comes from the Latin ob+via, meaning by the wayside13. So the emphasis is not on discovery but on accessibility, and what is being looked for is a negative attribute i.e. that the skilled person would have come upon the claimed subject matter sooner or later and without having to display ingenuity. When introduced into statute law, an obviousness test tends become substituted for an enquiry into inventive character. Indeed, Judge Giles S. Rich argued that the introduction of obviousness standard into US law removed any separate requirement for inventive character, which he described as a rough-hewn stopgap with which the courts had filled in a void in the patent law, but which had now been replaced by a carefully worked-out statutory substitute of non-obviousness14.

Unfortunately life is not that simple. Many things are not obvious in the sense of readily accessible but do not involve ingenuity. A familiar example is the set of winning numbers for the next draw in the National Lottery. It is not difficult and mildly entertaining to devise groupings of familiar objects that would be difficult to trace collectively to the prior art15 but which do not achieve any unexpected effect or solve any technical problem. It is arguable that the point raised by Judge Rich had already been answered by the US Supreme Court in Graham v John Deere16 where it was held that the requirement for invention or patentable novelty had existed in US law since at least 1850, and that the new law had merely codified existing judicial precedents and introduced an enquiry as to the obviousness of the subject matter claimed as a prerequisite to patentability. In other words, to be patentable an invention must have patentable novelty and be free from objection on the ground of obviousness. Essentially the same point arose before the EPO Appeal Board17 where applicants argued that the significant question in relation to the obviousness of a claimed class of compounds was whether it was obvious to prepare any compound within the class, and not whether all the compounds within the class solved a technical problem. The Appeal Board rejected this argument on the basis that the extent of the patent monopoly should correspond to and be justified by the technical contribution to the art: it follows that there must be a positive technical contribution to justify a patent. Both discovery and accessibility can be important and both of them are habitually considered by the EPO and by national courts under the heading of "obviousness". One of the problems that we often face is to identify which of them is likely to be crucial in a case that we are currently handling.

The "scales of justice" approach

Do we need a test that is more sophisticated than the express provisions of the Convention? A litigation lawyer might say, following the approach of Judge Rich: "Why not rely on the statute? Inventiveness and obviousness are questions of fact. The parties should file their evidence in the usual way, and in courts working within the Common Law system that evidence can be tested by cross-examination. Then the Judge can weigh up the evidence and come to his decision." The common law tradition has until recently exhibited remarkable resistance to the development of a systematic test for inventive step. Anyone who has worked day-to-day with UK judges, barristers and solicitors knows that they are very able and could easily have evolved such a test, but that they were united in the view that it was undesirable to do so. White and Warden18 have defended the pragmatic British tradition on the ground of flexibility and said:

"For administrative convenience, inventiveness may come to be judged by some philosophical meter-stick and not by a pragmatic approach based on a full consideration of all the facts. This can only lead to the patent system becoming more divorced from reality."

The action between Graham and John Deere19 concerning infringement of US patent 2627798 provides an example of a court reaching its decision straightforwardly on the basis of the evidence adduced20. The invention concerned an improved clamp for clamping a long springy chisel-carrier to the frame of a plough. The patentees alleged that the patented construction enabled the chisel-carrier to flex over more of its length, and that this difference, though small, made the difference between success and failure. The patentees had an uphill battle because an explanation of the importance of improved flexing had neither found its way into the specification of their patent nor been mentioned while the application was being prosecuted before the Patent Office. But what turned difficulty into defeat was that their expert witness would not confirm that improved flexing was important as the following extract from his cross-examination demonstrates21:

"Q. Do you regard this small degree of flex in the forward end of the shank that lies between the pivot point and the point of spring attachment to be of any significance or any importance to the functioning of a device such as 798?

A. Unless you are approaching the elastic limit, I think this flexing will reduce the maximum stress at the point of pivot there, where the maximum stress does occur. I think it will reduce that. I don’t know how much.

Q. Do you think it is a substantial factor, a factor of importance in the functioning of the structure?

A. Not a great factor, no."

Unsurprisingly the Supreme Court believed the testimony of the patentee’s expert, and held that the patent was unenforceable.

The importance in US or UK infringement proceedings of having witnesses who are aware of the implications of what they are saying and are on their guard against making incautious remarks cannot be over-emphasized: this is not to say that a witness should be partisan or frame his answers to technical questions in the light of what he or she imagines to be the legal implications of the answer, which will simply result in him being disbelieved22. Witnesses at European oral proceedings often give similar self-destructive testimony. Many of us in European opposition proceedings have had the experience of encountering the opposing representative unexpectedly accompanied by the inventor or by another technical person, and then having to judge whether to object to his giving evidence on the ground that it has not been notified in advance or to permit the accompanying person to have his say, taking the view that he is as likely through inexperience to say things that damage his case as he is to say things that improve it.However, both in the UK and in the USA, the courts have found through experience that it is not enough simply to listen to the witnesses and weigh their evidence. They have identified the need for a structured framework within which they can consider the evidence adduced. That put forward in Graham v John Deere23 now provides the leading approach under US law and involves the following steps:

  • Determining the scope and content of the prior art.
  • Ascertaining the differences between the prior art and the claims at issue.
  • Resolving the level of ordinary skill in the pertinent art.
  • Against this background, determining the obviousness or nonobviousness of the subject matter claimed.
  • Evaluating secondary considerations that provide indicia of obviousness or nonobviousness, such as commercial success, long-felt but unresolved needs, failure of others, etc. that can be used to give light to the circumstances surrounding the origin of the subject matter sought to be protected.

The framework suggested by the Court of Appeal in Windsurfer v Tabur Marine24 is of comparable status in the UK and is strikingly similar to the US test. It involves the following steps:

  • Identifying the inventive concept embodied in the patent in suit.
  • Assuming the mantle of the normally skilled but unimaginative addressee in the art at the priority date and imputing to him what was, at that date, common general knowledge in the art in question.
  • Identifying what, if any, differences exist between the matter cited as being "known or used" and the alleged invention.
  • Asking whether, viewed without any knowledge of the alleged invention, those differences constitute steps which would have been obvious to the skilled person or whether they require any degree of invention.

Both frameworks are intended to guide us in our approach towards a decision; when the time comes to make the decision we are left weighing the evidence as before. Depending upon our point of view this can be regarded as a beneficial means of preserving flexibility or as a failure to provide guidance where it is most needed. But as working patent attorneys or examiners we have time measured in hours to analyze a situation and make a recommendation that, if there is litigation, will be called on to survive the scrutiny of teams of litigators and experts whose time is measured in hundreds or possibly thousands of hours. We should therefore remind ourselves from time to time that our professional work is very difficult, and that it is foolish to ignore any tool than makes our task simpler or the outcome more reliable. A test that can be applied in an algorithmic manner such as that decided on by the EPO and that provides a consistent approach to the task of decision-making has clear advantages over an approach that involves having to decide anew for each case what is the appropriate legal framework before an analysis of the factual matrix can be undertaken.

Collocations and combinations

If we accept the view that new function or result is the invenium or discovery that justifies grant of a patent, then arguably that provides the scintilla that was called for in Parkes v Crocker25 and that was alluded to by the US Supreme Court in Cuno v Automatic Devices26, a requirement for a new function or result providing a more realistic and objective standard than a requirement for a flash of creative genius whilst nevertheless following the same general line of thought. Imposing a requirement of this kind amounts to the adoption of an "effect-based" approach27 and could in principle provide a useful and objective test that would command widespread acceptance.

The rule against collocations is an early formulation of an effect-based algorithmically applicable approach. It prohibits patenting a claim to a combination of known integers unless there is an unexpected new function or result that flows from the combination itself. The rule is potentially of wide application since, as Markey J., who was then chief judge of the US Court of Appeals for the Federal Circuit, memorably said: "Only God works from nothing. Man must work with old elements."28 To a reader steeped in recent case law, the frequency with which UK and US judges used to rely on the rule comes as a surprise.

An early statement of the rule by the US Supreme Court appears in Pickering v McCulloch29 as follows:

"In a patentable combination of old elements, all the constituents must so enter into it so that each qualifies every other; to draw an illustration from another branch of the law, they must be joint tenants of the domain of the invention, seized of every part per my et per tout, and not mere tenants in common with separate interests and estates. It must form either a new machine of a distinct character and function or produce a result due to the joint and cooperating action of all the elements, and which is not the mere adding together of the separate contributions. Otherwise it is only a mechanical juxtaposition and not a vital union."

By 1938, the rule had become so familiar that it was enough for the US Supreme Court to say, as it did in Lincoln Engineering Co v Stuart Warner Corp30:

"The mere aggregation of a number of old elements which, in the aggregation, produce no new or different function or operation than that theretofore performed or produced by them is not patentable invention."

The UK courts applied the same rule since the decision in Crane v Price31, and Lord Tomlin stated it the House of Lords in British Celanese v Courtaulds32 as follows:

"It is accepted as sound law that the mere placing side-by-side of old integers so that each performs its own proper function independently of any of the others is not a patentable combination, but where the old integers when placed together have some working relation producing a new or improved result, then there is patentable subject matter in the working relationship brought about by the collocation of the integers."

The steep decline in popularity that the rule has undergone in the UK since 1936 is a further surprise given its practical value when appropriately applied. It is even more surprising to come upon a paper written in 1943 by a U.K. Patent Agent33 advocating the adoption of a collocations test on the basis of US jurisprudence, and as if the test had been unknown to UK law whereas it had been restated by the House of Lords only a few years previously and in the early years of the twentieth century had been applied by Fletcher-Moulton L.J. whose reputation amongst UK patent lawyers has always been high. The article was not influential, and the decline continued so that in High Court infringement and revocation proceedings other tests are preferred and the collocations rule is almost never invoked. One possible explanation is that the collocations rule tests for the positive character of a discovery in or arising from the claimed subject matter, whereas the statutory obviousness standard that had been introduced in 1932 focuses on the negative characteristic of prior accessibility to the skilled person. Another explanation could be simply a change in fashionable viewpoint.

In the US, the rule against collocations had been falling into disrepute even before 1952 in the light of controversial opinions of the US Supreme Court in Funk Bros. Seed Co. v Kalo Inoculant Co.34 and infamously in Great A. & P. Tea Co v Supermarket Corp35. Nevertheless US Supreme Court continued to apply the rule after 1952 in its decisions in Anderson’s-Black Rock Inc. v Pavement Savage Co36 and in Sakraida v AG Pro, Inc37. In Sakriaida, as in an number of previous cases, the court stripped away successive features from the claim, traced them to the prior art and found that they did not make a synergistic contribution, whilst acknowledging that overall the invention was better than the prior art and had been commercially successful. This approach is not calculated to inspire confidence amongst practitioners. Elevation of the requirement for new function or result into a requirement for synergism gave rise to a tidal wave of disapproval from both judges and academic writers. The Court of Appeals for the Federal Circuit responded by pointing out in Stratoflex Inc. v Aeroquip Corp.38 that a requirement for synergism is nowhere found in 35 USC, that its absence has no place in evaluating evidence concerning obviousness and that the allegedly more objective approach in Graham was derived from the language of the statute and was fully adequate for the task. Since that time the collocation test has also been in steep decline in the USA.

Both in the UK and in the USA, therefore, attempts to create an effect-based test using the prohibition on collocations failed because of legislative changes and because of disapproval on the part of practitioners, that disapproval flowing from inappropriate application of the test by the courts.

Under the EPC, the Appeal Boards have distinguished mere aggregations of features from combination inventions, and have been prepared to divide a technical problem into two or more independent partial problems. However, cases of this type have occurred only in insignificant numbers compared to those which have been dealt with by the more usual route of problem/solution analysis.

The EPO Approach

The concept of inventive step as explained in the successive decisions of the Boards of Appeal of the EPO provides a framework for solving disputes concerning obviousness, but it has also become fundamental to the resolution of other issues within the EPO, for example unity of invention, support in the description for claimed subject matter, and whether a particular description is enabling. It has two principal features:

  • Analysis is carried out within the formal framework of the problem and solution approach.
  • The analysis is effect-based.

Problem and solution analysis

Problem and solution analysis determines the citations that an examiner is likely to select when he puts forward an objection as to lack of inventive step, and the arguments that are most advantageously put forward in response to that objection. As those who study EPO Appeal Board decisions rapidly realize, EPO staff, from individual examiners to appeal board members are trained to ask themselves the following five questions:

  • What is the field of the invention?
  • What is the most relevant prior art in that field?
  • Starting from that prior art, what was the technical problem to be solved?
  • Was it inventive to identify the technical problem? If not: -
  • Was it inventive to find the particular solution provided by the claimed subject matter?

The scope of the claimed technical field is fundamental to problem/solution analysis because the starting point or primary reference that is used to formulate the technical problem is normally a document or instance of prior use within the claimed field. The applicant or patentee has the option to decide whether to claim the invention within a broad or narrow technical field and correspondingly to increase or decrease the range of citations which are potentially relevant. That proposition is supported by the following extract from the decision in T 570/9139:

"If … a person skilled in the art prefers and decides to start from a specific compressor piston, he can further develop that piston but at the end of that development the normal result will still be a compressor piston and not an [internal combustion engine] piston. In other words, the chosen closest prior art must be able or at least potentially able, perhaps after modifications, to obtain the same effects as those resulting from the claimed embodiment... Otherwise, such starting point prior art could not lead a skilled person in an obvious way to the claimed invention."

It should be noted that the restriction must appear in or be introduced by amendment into the claims, and a mere statement in the description will not suffice.

The natural approach of an examiner or opponent is to base his objection on the structurally closest prior art, but that may not be a fair starting point if the reference that he has selected does not also associate the disclosed structure with properties that are relevant to the technical problem. There is therefore scope for argument that the primary reference should be a different document from that selected by the Examiner, and for basing the preamble or classifying part of a two-part claim on what is disclosed in that other document. To make such an argument work, we need to rely on a specific document or perhaps on a specific instance of prior use and not on a mere abstract generalization.

In T 0570/9140, the Board suggested the following basis for selecting the starting point disclosure:

"It seems that in most cases it is appropriate to look particularly at those prior art disclosures which have something to do, be it explicitly or implicitly, with the problem set out in the application or opposed patent. These disclosures will normally either be capable of being further developed to arrive at the claimed invention or at least point thereto. The closest prior art, i.e. that which provides the strongest basis for an obviousness objection, will then be selected from the above-mentioned disclosures."

A slightly different statement of the principles for selecting a starting point disclosure is found in the following extract from the opinion in T 0073/9541:

"During the oral proceedings, the Appellant … argued that D1 required the minimum of structural and functional modifications and should, therefore, be regarded as the closest state of the art. The Board cannot follow that reasoning. The normal practice of the problem and solution approach requires, first, to consider whether a given teaching is directed to the same purpose or effect as the invention, and only subsequently to examine the compositional differences. It is sufficient to refer to the Case Law of the Boards of Appeal of the European Patent Office, Third Edition 1988, page 111 (English Version; chapter D. Inventive step, 3.1 Determination of closest prior art – general), where numerous decisions are quoted which all specify that a document cannot qualify as the closest prior art merely because of similarity in the composition of the products, but that a prerequisite therefor is that its suitability for the desired purpose has also been described."

In order for the EPO to acknowledge the existence of an inventive step, the definition of a technical problem is mandatory; see ICI/Containers42 where Appeal Board said:

"The provisions of Rule 27(1)(d) require that the description shall disclose how the invention can be understood as the solution to a technical problem. Indeed, the inventive step may be considered as a step from the technical problem to its solution. If, therefore, the requirements of the above rule are neither satisfied by the original description, nor, after request, by an amendment, it will emerge that an invention within the meaning of Article 52 does not exist. On the other hand, if the subject-matter of an independent claim, for which there is sufficient disclosure, is judged as being inventive in character, it must always be possible to derive a technical problem from the application."

In Case T 20/81 (SHELL/Aryloxybenzaldehydes)43 the Board observed that:

"The nature of the problem should be determined on the basis of objective criteria ... This requires the assessment of the technical success vis-à-vis the state of the closest art."

The relevant criteria were explained early on in the working life of the EPO where the appeal board explained in forthright terms in BASF/Metal refining44 that technical analysis within the problem/solution approach is what the EPC requires, and that circumstantial evidence of the kind referred to by the US Supreme Court in Graham v John Deere45 is of low persuasive power:

"When assessing inventive step ... it is not a question of the subjective achievement of the inventor ... It is rather the objective achievement which has to be assessed. As in the case of novelty, inventive step is an objective concept. Objectivity in the assessment of inventive step is achieved by starting out from the objectively prevailing state of the art, in the light of which the problem is determined which the invention addresses and solves from an objective point of view ... and consideration is given to the question of the obviousness of the disclosed solution to this problem as seen by the man skilled in the art and having those capabilities which can be objectively expected of him ... The appellant sees the fact that the steel industry has passed by the method as applied for, despite the significant economic contribution it makes to solving the environmental problems in this field, as an indication of the presence of inventive step. The Board takes the view that, as against the assessment of inventive step from the objective point of view ... a mere investigation for indications of the presence of inventive step is no substitute for the technically skilled assessment of the invention vis-à-vis the state of the art, pursuant to Article 56 EPC."

It is notable that after a period of experimentation with extensive investigation of surrounding circumstances and generous orders for disclosure of documents, the UK courts have come to realize the benefits of the focus on primary evidence advocated in BASF and the need not to permit secondary evidence e.g. of commercial success to become so voluminous and complex that it obscures the fact that it is no more than an aid to the assessment of the primary evidence46.

Problem/solution analysis is effect-based

Although European technical analysis is conducted within the formal framework of problem/solution analysis, the outcome principally determined by whether the claimed subject matter leads to a new effect, some new function or advantage that cannot be predicted from the teachings of the prior art references considered collectively47. Szabo made that clear, for the chemical field at least,48 when he said that:

"The practice of the Board of Appeal (Chemistry) has been relying on an effect-centered problem and solution approach to the question of inventive step. It seems that the principles of this approach have been applied to ordinary cases as well as to other kinds which have not been satisfactorily resolved in the past in a manner which is consistent through all fields of technology."

This observation is supported by the decision in T 0939/9249, which concerned a class of herbicidal triazole sulphonamides. The dispute was whether the whole class of compounds had to herbicidal in order to establish patentability, or whether it was enough for the applicants to show that:

(a) some of the claimed compounds were herbicides; and

(b) the cited art did not teach the skilled person to make any compound within the class.

The applicants argued that the Board need only consider whether the skilled person would make the claimed compounds starting from the prior art teachings – i.e. the relevant question was what the public would do, not what the inventor had achieved. The Board rejected the applicant’s argument in uncompromising terms, and based its opinion on the legal principle that the extent of the patent monopoly should correspond to and be justified by the technical contribution to the art that is contained in the specification. Significantly, it explained that although the analysis was expressed in terms of a technical problem and its solution, that problem could be a reconstruction from what the invention achieved in relation to the prior art. The relevant passage in the decision reads:

"…the notional ‘person skilled in the art’ is not to be assumed to seek to perform a particular act without some concrete technical reason: he must be assumed to act not out of idle curiosity but with some specific technical purpose in mind.

For this reason the boards of appeal consistently decide the issue of obviousness on the basis of an objective assessment of the results achieved by the claimed subject matter, compared with the results achieved according to the state of the art. It is then assumed that the inventor did in fact seek to achieve these results and therefore these results are taken to be the basis for defining the technical problem …"

The Board went on to say that mere structural ingenuity was not sufficient. If the result that the skilled person was seeking to achieve was simply obtaining further chemical compounds, then all known chemical compounds were equally suitable as starting points and all known methods of transformation might be used, so that the selection of particular compounds to be made was a mere arbitrary choice. For that reason

"…the selection of such compounds, in order to be patentable, must not be arbitrary but must be justified by a hitherto unknown technical effect which is caused by those structural features which distinguish the claimed compounds from the numerous other such compounds."

A similar situation arises in the field of genetic engineering where the EPC rules have recently been updated to take account of the recent EU Biotechnology Directive. That Directive proved politically controversial and was adopted following a decade of debate. All the legislative changes proposed in that Directive were therefore the subject of intense scrutiny by politicians and by interested parties. Paragraphs 2 and 3 of new rule 23e EPC50 read as follows:

"(2) An element isolated from the human body or otherwise produced by means of a technical process, including the sequence or partial sequence of a gene, may constitute a patentable invention, even if the structure of that element is identical to that of a natural element.

(3) The industrial application of a sequence or partial sequence of a gene must be disclosed in the patent application."

The significance of paragraph (3) is discussed in an explanatory Notice from the EPO51 as follows:

"In paragraph (3) the general requirement already present in Rule 27(1)(f) EPC that the description should where appropriate indicate the way in which the invention is capable of exploitation in industry is given specific form in relation to sequences and partial sequences of genes. Thus where such sequences are the subject matter of an invention, it is necessary to indicate in particular what function is performed by the sequence and the protein built from it."

Although the above rule change has been defined in terms of the utility requirements of the EPC, it is consistent with the opinions on inventive step set out above. A claimed genetic sequence is merely an arbitrary selection from amongst the possible genetic sequences unless it provides the instructions for making a protein having a particular technical effect, which must be disclosed in the specification. The technical effect must also, presumably, be unexpected. There are, as yet, no cases to guide practitioners as to what kind of "function" will satisfy this requirement, but it is likely that vague or speculative statements of function will not do so.

Obviousness in the light of the identified problem

Following establishment that a non-trivial technical problem existed and identification of the technical problem, a decision is required whether, having regard to the disclosure of the primary source and any secondary sources (including the common general knowledge in the art), it was inventive to identify the problem or to find the claimed solution. Experience shows that the enquiry is much easier than it would be if we did not know what we are looking for: we are not in the position of Inspector Gregory52 gazing at a patch of trampled mud in Dartmoor and having the unstructured task of looking for anything in the mud that suggested how a victim under investigation came to have been fatally injured. Instead our position is closer to that of Sherlock Holmes who had the well-structured task of checking whether or not there was a half-burned match buried in the mud, the presence of such a match tending to confirm a theory that he had already formed about how the victim came to have met his fatal injury. In our field, we can make a well-structured investigation whether or a surprising new function or result flows from the claimed subject matter, and that is easier than conducting an unstructured enquiry involving metaphysical speculation e.g. about the distinction between an inventor and a skilful mechanic.

Once the technical problem has been defined, it is surprisingly easy to ascertain whether the new function or advantage is disclosed or suggested by the prior art sources when considered collectively. Whether or not there is a surprising new function or advantage is usually decisive: it is more persuasive to argue that the invention provides an unexpected advantage than it is to argue that that technical success was uncertain so that it was not obvious to try, that the invention has been a commercial success, that a secondary reference is in a remote field or that it was too old or obscure to have been seriously considered by the skilled person, although of course all of the latter arguments are in principle available and sometimes succeed.


As explained above, since ability to identify a technical problem vis-à-vis the closest prior art is a necessary condition of patentability under the EPC, and since technical problem is defined by reconstruction from the effect, i.e. the new function or result, discovered by the patentee, problem/solution analysis and the older collocations approach can be regarded as opposite sides of the same coin. However, it will also be apparent that the EPO Appeal Boards have succeeded in making an effect-based approach acceptable to a broad cross-section of those working in the field of patents, whereas the earlier attempt based on the collocations rule failed both in the UK and in the USA. The significant difference can be identified that in problem/solution analysis the tribunal is positively required to look for a new function or result discovered by the patentee and to reconstruct a technical problem. As previously explained, that task was arguably performed imperfectly by the US courts that followed the collocations approach and were prone to considering features in isolation and dismissing them as being inconsequential, as is so easy in hindsight (the "onion-peeling approach").

One of the most notorious examples of the "onion-peeling approach" was in the Great A. & P. Tea Co. case53, in which the invention concerned an improved check-out station for a supermarket having an elongated counter, a three-sided rack for moving goods from a waiting position to a check-out position and guide rails for keeping the rack in place. The US Supreme Court picked off the claimed features one by one and dismissed them for the following reasons:

  • The counter did what it had always done – it supported merchandise at a convenient height and it was commonplace to make it of any desired length.
  • The three-sided rack would draw or push goods within it from one place to another – just what any such rack would do on any smooth surface.
  • The guide rails would keep the rack from falling off the counter, as guide rails have always done.

The Court concluded that "two and two have been added together and still they make four" and held the patent to be invalid.

The key advantage of the European approach is that by requiring the identification of a technical problem as a preliminary step, it gives the tribunal a positive criterion against which it should test the significance of the observed differences, and therefore requires the tribunal to do more than pick the invention apart negatively using the "onion-peeling approach". Applying a European approach to the facts in the A & P case, the closest prior art was a conventional check-out counter, the patented check-out counter provided more speedy check-out and reduced queuing time by 30%, and the objective technical problem starting from the closest prior art was how to speed up check-out at a supermarket check-out counter, which is a plausible technical problem in a device of the above kind. The question would then have been whether when the primary prior art and the secondary art considered collectively suggested the claimed invention. If the US Supreme Court had adopted a similar approach, and if the patentees had been given credit for their technical achievement in speeding up the check-out operation, the appearance of injustice in the A & P decision would have been avoided, and the outcome might have been different.

As is apparent from the above discussion, it is implicit in an effects-based approach that selection of technical features plus an associated advantage is a positive indicator of patentability under European patent law. The same positive indicator is also mentioned in a number of recent decisions from the CAFC54. The existence of such an indicator should not come as a surprise because selection plus advantage is a force of nature. In biology it drives the process of evolution and has given rise to the diversity of plants and animals that we see in our daily life. Technology can be regarded as a human "meme"55 which evolves or develops with time and is subject to an evolutionary selection pressure because good and workable concepts and artifacts are selected and developed, whereas erroneous concepts and unworkable artifacts become rejected and abandoned. An effects-based approach as has been adopted by the EPO is therefore truly considering aspects of inventions that are of fundamental, and not merely superficial, significance.

1 J.R.R. Tolkien, "The Simarillion", Ainulindale.

2 Singer, The European Patent Convention, English Edn. 1995 by Raph Lunzer, see also Biogen v Medeva [1997] RPC 1 at p. 41

3 C.I.P.A. Guide to the Patents Acts, 4th Ed at para. 3.21

4 Hanns Ullrich, "Standards of Patentability for European Inventions", IIC Studies, Vol. 1, Max-Plank-Institute, Munich 1977; Heinz Bardehle, "Inventive level in the light of the European Patent Convention and German practice", [1978] EIPR 11 (November 1978)

5 21 Jac 1, c. 3 (1623): a patent could be granted to the true and first inventors of any manner of new manufacture. That could include a person who imported the invention into England, see the quotation by T.A. Blanco White, Patents for Inventions, 4th Ed at 5-105 from Edgeberry v Stevens (1691) 1 WPC 35: "Whether learned by travel or study it is the same thing." But it should be borne in mind that a man who made a sea voyage at that time put his life at risk.

6in 1932, Patents and Designs Act, 1932.

7 in 1952, see 35 USC 103

8 Parkes v Cocker (1929) 46 RPC 241 at p. 248.

9 Hotchkiss v Greenwood 52 U.S. (11 How.) 248 (1850).

10 Cuno Engineering Corp. v Automatic Devices Corp., 314 U.S. 84, 91; 51 U.S.P.Q. 272, 275 (1941) per Douglas J., see the discussion of this case in Graham v John Deere Co., 383 U.S. 1, 148 U.S.P.Q. 459 (1966)

11 Case T 455/91 GENENTECH/Expression in yeast (OJ 1995, 684)

12 U.K. Patents Court, 8th November 2000.

13 For an example of the word used in precisely this sense in literature, see an account of the travel of a party of knights along a path towards a dragon’s cave in J.R.R. Tolkien, Farmer Giles of Ham, Unwin Paperbacks, 1975 at p. 57: "The knights were discussing points of precedence and etiquette and their attention was distracted. Otherwise they would have observed that the dragon marks were now obvious and numerous."

Obvious also means that which can readily be deduced from what is apparent, as shown from the following conversation of Sherlock Holmes in The Red-Headed League:

" ... "beyond the obvious facts that he has at some time done manual labour, that he takes snuff, that he is a freemason, that he has been in China, and that he has done a considerable amount of writing lately, I can deduce nothing else.’

Mr. Jabez Wilson started up in his chair, with his forefinger upon the paper, but with his eyes upon my companion.

‘How, in the name of good fortune, did you know all that Mr. Holmes?’ he asked. ‘How did you know, for example, that I did manual labour. It’s as true as gospel, and I began as a ship’s carpenter."

‘Your hands, my dear sir. Your right hand is quite a size larger than your left. You have worked with it and the muscles are more developed.’

‘Well the snuff then and the Freemasonry?’

‘I won’t insult your intelligence by telling you how I read that, especially as, rather against the strict rules of your order you use an arc and compass breastpin.’ .....

Mr. Jabez Wilson laughed heavily. ‘Well I never!’ said he. ‘I thought at first you had done something clever, but I see there was nothing in it after all.’

14 "Escaping the tyranny of words ... is evolution in legal thinking impossible" (1978) 60 Journal of the Patent Office Society 271.

15 For example a table having a built-in baby bath and an attached can-opener; the more objects you specify the harder it is to find a reference specifying that the specified objects should be assembled or grouped together.

16 supra at note 10.

17 T 939/92 AGREVO/Triazoles

18 A.W. White and J.C. Warden, "The British Approach to obviousness" Annual of Industrial Property Law, 1977 (J.C. Warden, ed., 1978)

19 383 U.S. 1, 23; 148 USPQ 459 (1966)

20 Of course this begs the question of how an advocate adduces the correct evidence unless he knows in advance what he is looking for. See Sherlock Holmes again, this time in Silver Blaze:

"Holmes took the bag, and descending into the hollow he pushed the matting into a more central position. Then stretching himself upon his face and leaning his chin upon his hands he made a careful study of the trampled mud in front of him.

‘Halloa!" said he, suddenly, ‘what is this?’

It was a wax vesta [match], half burned, which was so coated with mud that it looked at first like a little chip of wood.

‘I cannot think how I came to overlook it," said the inspector with an expression of annoyance.

‘It was invisible, buried in the mud. I only saw it because I was looking for it.’"

21 supra, see note 8.

22 see Ikarian Reefer [1993] FSR 563.

23 supra at n. 10.

24[1985] RPC 59 at 73-74.

25 n. 8 supra

26 n. 10 supra

27 See Szabo (1995) 26 I.I.C. 457

28Why not the Statute, 65 Journal of the Patent Office Society 331.

29 104 U.S. (14 Otto) 310, 318.

30 303 U.S. 545, 37 U.S.P.Q. 103 (1938).

31 1 WPC 393 (1842).

32 (1935) 52 RPC 171 at p, 187 and at p. 193-194.

33 F.W. Hacking, Patentable Novelty, (1942-43) 61 CIPA Transactions 170.

34 333 U.S. 127, 76 U.S.P.Q. 280 (1947).

35 340 U.S. 147, 87 U.S.P.Q. 305 (1950), see Paul Cole, Supermarket Check-outs Revisited, Patent World, March 1988, pp. 12-17.

36 396 U.S. 57, 163 U.S.P.Q. 673 (1969).

37 425 U.S. 273, 189 USPQ 449 (1976).

38 218 USPQ 871, 880 (1983).

39 AE PLC/Pistons

40 AE PLC/Pistons, referred to above

41 ENICHEM SYNTHESIS/Solid stabilizer composition, also available from the EPO web-site.

42 T 26/81, OJEPO 1982, 211.

43 OJEPO 1982, 217

44 T 24/81, OJEPO 1983, 133.

45 supra at n. 10.

46 see Molnlycke v Proctor & Gamble [1990] RPC 49 and 498 and Hoechst Celanese v B.P. Chemicals [1997] RPC 547, see also P.G. Cole, Discovery of Documents in Patent Litigation, [1998] 3 IPQ 205 at pp. 234-7.

47 The existence of an unexpected new effect may be a necessary condition for patentability but it is not a sufficient condition. If the prior art when considered collectively suggests some other advantageous new effect, then arguments concerning mere "bonus effect" or "one-way street" become relevant, and inventive step may be denied.

48 G.S.A. Szabo, "The Problem and Solution Approach to the Inventive Step", [1986] 10 EIPR 293-303.

49 AGREVO/Triazoles

50 OJ EPO 7/1999 437, 439.

51 OJ EPO 8-9/99 573, 581

52 Silver Blaze, supra, n. 20.

53 supra

54 "… one way for a patent applicant to rebut a prima facie case of obviousness is to make a showing of ‘unexpected results,’ i.e. to show that the claimed invention shows some superior property or advantage that a person of ordinary skill in the art would have found surprising or unexpected." In re Soni 34 USPQ2d 1684, 1687, quoted with approval by the CAFC in, for example, In re Nancy G. Mayne et al, 17 January 1997, In re Michael Geisler et al, 7th July 1997 and in Richardson-Vicks v Upjohn, 26th September 1997.

55 A "meme" is defined to mean a unit of replication within a human culture or just possibly sometimes an animal culture, see Susan Blackmore, The Meme Machine, Oxford University Press 1999.

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