Patents and the meaning of obvious

These 4 requirements are:

1. The invention must be new,

2. It must involve an inventive step,

3. It must be capable of industrial application, and

4. The grant of a patent for it must not be excluded by the PA 1977.

One of the requirements for an invention to be patentable, is that the invention must involve an “inventive step”. Under section 3 PA 1977, “an invention shall be taken to involve an inventive step if it is not obvious to a person skilled in the art, having regard to any matter which forms part of the state of the art”. Therefore an invention that involves an inventive step is one that was not obvious, at the time of applying for a patent, and, consequently, an invention that does not involve an inventive step is one that was obvious. As well as being one of the most important requirements of patentability, the inventive step is also the most problematic when it comes to its exact meaning. This uncertainty is due to the vagueness of some words making up section 3, and its equivalent in the EPC article 56, especially the word “obvious”.

The consequence of this uncertainty is that this provision, as well as its counterpart, has proved everything but easy to apply. The difficulty here is to assessed precisely when an invention was or not obvious. To remedy this difficulty both the European Patent Office (thereafter “EPO”) and the UK Courts have developed their own personal approach of this problem, despite the quasi-identical wording between section 3 and article 56. They broke down the statutory requirement into, respectively, a 3 and 4-step test in order to help both the judges, when assessing obviousness, and the patentees, when deciding whether their invention is worth patenting or not.

The EPO and UK tests to assess obviousness

The EPO test

In order to harmonize the different approaches to obviousness, and in the end to inventive step, that was then in force in the 13 Member States of the EPC, the EPO set out, in its early days, to develop a test, designed to determine the presence or not of an inventive step, which would be as objective and transparent as possible. This test became the backbone of the so-called “problem and solution approach”. As stated in the Guidelines for examination at the EPO, “when assessing inventive step the examiner normally applies the problem and solution approach”.

The idea here has been to adopt a structured test based on a consistent sequence of questions to be investigated by the examiners. This meant breaking down the statutory definition of inventive step, under article 56, in three steps:

1. Determining the closest prior art.

2. Establishing the technical problem to be solved, and

3. If Considering whether or not the claimed invention, starting from the closest prior art and the technical problem, would have been obvious to the skilled person.

The test was intended to be as objective as possible. This was thought to be achieved mainly by basing the test on three objective concepts, the so-called “generally applicable working principles” as defined in the Guidelines. These three concepts are:

— The closest prior art: combination of features derivable from one single reference that provides the best basis for considering the question of obviousness.

— The technical problem to be solved: established by studying the application (or the patent), the closest prior art, and the different terms of features (either structural or functional) between the invention and the closest prior art.

— The skilled person: notionally skilled individual, or group of people in some cases (eg. for advanced technologies), equipped with attribute such as skills, background knowledge and qualifications relevant to the field in which he works. It is through the eyes of that person or team of persons that obviousness is assessed.

As such, rather than asking whether an invention in itself was obvious, the EPO asks whether the solution that this invention provides to a determined problem would have been obvious to a person skilled in the art at the priority date of the invention. The value of this test is that it enables to approach the task of answering the question of obviousness in a structural way. Far from being flawless, this test has been criticised in the UK for its use of hindsight, namely ex post facto analysis, and the fact that it is unnecessarily artificial because many inventions developed without having a problem in mind. Perhaps the most important objection is that, while the EPO test is presented as being applicable to all types of research, there are situations where its use is inappropriate. Indeed it is not easy to formulate a problem for many inventions, particularly in the chemical-pharmaceutical field.

The UK test

Whatever the current state of the law at the EPO, UK Courts have largely remained isolated from and resistant to the adoption of the “problem and solution approach” and its test for assessing obviousness. Instead, when considering the way in which obviousness is to be assessed they have so far relied on the test set out in 1985 by Oliver L. J. in the so-called Windsurfer case.

The Windsurfer case concerned a patent for a sailboard, which had been already granted to the plaintiffs, the validity of which was raised as a defence to infringement proceedings brought against the defendant. To tackle the question of obviousness and thus of lack of inventive step, which was alleged by the defendant, Oliver L. J. set out to apply a 4-step test:

1. Identify the inventive concept embodied in the patent suit

2. Assume the mantle of the normally skilled but unimaginative addressee in the art at the priority date and impute to him what was, at that date, common general knowledge in the art in question.

3. Identify what, if any, differences exist between the matter cited as being [the state of the art] and the alleged invention.

„ Ask whether, viewed without any knowledge of the alleged invention, those differences constitute steps, which would have been obvious to the skilled man or whether they required a degree of invention.

In more positive terms, the Courts must first identify the differences that exist between the state of the art and the alleged invention. Then they must consider whether those differences were or not obvious, when viewed through the eyes of a skilled but unimaginative person.

Here again, as the EPO test, the UK test is based on several objective concepts (state of the art, skilled person, …) aimed to make it as objective as possible, namely applicable to all given types of research and situation whatsoever. Its value, like the EPO test, of this test is that it enables the Courts to approach the task of answering the question of obviousness in a structural way. Yet the deficiency of this analysis is that it over-elaborates the statutory definition of the inventive step requirement without reducing the confusion and uncertainty that has long been associated with it. Indeed it does not provide any guidance on the required evaluation itself and ends up merely restating it. At last the way in which Oliver L. J.’s original wording has been varied in subsequent cases (eg. Moelynycke AB v. Proctor and Gamble Ltd, 1992) is yet another proof of the deficiency of this test.


From this brief comparison of the EPO and UK tests some conclusions can be drawn:

– Both tests aim at answering whether an invention was obvious or not, and claim to be as objective as possible.

– Despite the fact they are both based on objective concepts, they both leave a certain degree of appreciation or subjectivity to the judges.

– This demonstrate how complex the question of assessing obviousness is and that there is no flawless way to achieve that aim.

In recent year however there has been a growing belief that the EPO test ought to be used in the UK. In part this has been motivated by a realization that the two tests may not be conceptually so different as they first appeared (they both share common concepts). Perhaps the strongest support for the use of the “problem and solution approach” and its test for assessing obviousness in the UK comes from the House of Lords’ decision in Biogen v. Medeva. The advantage of such an evolution would be at least to have a harmonised test in Europe of assessing whether or not an invention present an inventive test.

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