Inventive Step (and Level of Invention) Explained

In his presentation on "Inventive Step In Current EPO Practise" (APLF Web Seminar, May 17, 2006) Walter Maiwald [Maiwald@maiwald.de] of Maiwald Patentanwalts GmbH discussed
the steps associated with the "problem and solution approach" derived from Rule 27 EPC which is (not obligatory under T 465/92, OJ 1996, 32 but) almost always applied by the Appeal Boards:

(i) determining the "closest prior art",

(ii) establishing the "objective technical problem" to be solved, and

(iii) considering whether or not the claimed invention, starting from the closest prior art and the objective technical problem, would have been obvious to the skilled person.

According to Dr. Maiwald, since using the invention as the search criterion for finding the "starting point" invariably favours a hindsight analysis, the analysis normally starts from the problem (left to be overcome in the prior art) both as described or implied (e.g. by the discussion of disadvantages of the prior art) in the specification.

In order to formulate the technical problem, one studies the application (or the patent), the closest prior art and the difference (also called "the distinguishing feature(s)" of the invention) in terms of features (either structural or functional) between the invention and the closest prior art and then formulates the technical problem. The "objective technical problem" means the aim and task of modifying or adapting the closest prior art to provide the technical effects that the invention provides over the closest prior art.

The objective technical problem derived in this way may not be what the applicant presented as "the problem" in his application. The latter may require reformulation, since the objective technical problem is based on objectively established facts, in particular appearing in the prior art revealed in the course of the proceedings, which may be different from the prior art of which the applicant was actually aware at the time the application was filed. In particular, the prior art cited in the search report may put the invention in an entirely different perspective from that apparent from reading the application only.

In the third stage, the question to be answered is whether there is any teaching in the prior art as a whole that would (not simply could, but would) have prompted the skilled person, faced with the objective technical problem, to modify or adapt the closest prior art while taking account of that teaching, thereby arriving at something falling within the terms of the claims, and thus achieving what the invention achieves. According to Dr. Maiwald,

Where no evidence is available which supports an improvement over the closest
art, the EPO will often assume that the technical problem was merely to provide
an alternative without improvement – this may be considered as obvious, where an
improvement would have been unobvious. Where the specification reflects embodiment examples which perform worse than the prior art comparisons, the EPO will often conclude that the claimed invention does not solve the problem over the breadth of the claim, and the claim is therefore at least partly not based on an inventive step. On the other hand, The absence of any reference in the prior art which expressly addresses the technical problem solved by the claimed invention, is generally a strong indicator of inventive step.

Thus, solutions to new problems, or better solutions to known problems, are most-likely to be patentable. However, where a feature combination was obvious to achieve some advantage, the occurrence of an unexpected further "bonus effects" advantage does not generally constitute inventive step. (e.g. T 21/81, OJ 1983, 15; T 231/97).

"Level of Invention," on the other hand, is a relative degree of change to a previous system (or solution) as a result of the solution of an inventive problem (one containing a contradiction). This term was introduced by author G. S. Altshuller in "TRIZ," (a Russian acronym for "Teoriya Resheniya Izobretatelskikh Zadatch," a theory of solving inventive problems sometimes referred to as Theory of Inventive Problems Solving), developed by Altshuller and his colleagues in 1946. Altshuller categorized patents by different degrees of inventiveness which he gave one of five levels:

1. Level 1 - Routine design problems solved by methods well known within the specialty. Usually no invention needed. example: use of coal for writing
2. Level 2 - Minor improvements to an existing system using methods known within the industry. example: graphite pencil (wrapped coal stick)
3. Level 3 - Fundamental improvement to an existing system using methods known outside the industry. example: ink pen (ink instead of coal)
4. Level 4 - A new generation of a system that entails a new principle for performing the system's primary functions. Solutions are found more often in science than technology. example: printer (another whole system for writing)
5. Level 5 - A rare scientific discovery or pioneering invention of an essentially a new system. example: electronic pen & paper (see Anoto)

More about TRIZ here, here, here, and here. Read the "TRIZ Journal."