Technical effect - BGH decision Schlossgehäuse

Technical effect - BGH decision Schlossgehäuse<br />

Technical effect is relevant for arguments before patent offices and patent courts.
In the recently published BGH leading decision Schlossgehäuse X ZR 51/21, the German Supreme Court (BGH) sets out the essential requirements for technical effect, which covers part of the examination of inventive step.

Technical effect and inventive step

In proceedings concerning the patentability of a patent in suit and inventive step, it is always of central importance which prior art is used as the starting point for the examination of inventive step and whether the claimed invention achieves a technical effect that goes beyond the prior art.

According to § 4 PatG, there is a fundamental presumption of inventive step if an invention ' not obvious to a person skilled in the art from the prior art'.

The essential approach before the German courts is therefore that the skilled person's thinking must be comprehensible. The examination of this also takes place in several steps in Germany, as in the BGH's leading decision Schlossgehäuse:

Here, a task was first determined that results from the technical problem / disadvantages of the prior art that the notional skilled person would see. In the present case, this task is to obtain a housing that combines stability and ease of assembly and, as far as possible, does not transfer spring forces to the electrical components.

It is then analysed whether and how the skilled person would have found the solution, the technical teaching that constitutes the invention. In the case of the lock housing, this is an omega-shaped design of the connecting conductors in accordance with feature l.

In the further discussion, the BGH stated that an omega-shaped configuration must have certain partial features (which the patent in suit also showed as a figure). On the other hand, the BGH considered it irrelevant whether and how the term "tulip-shaped" can be distinguished from the term "omega-shaped" in the linguistic usage of the patent in suit.

Features must be linked to a specific technical purpose

With regard to the features, the BGH emphasised the technical effect and the technical purpose. According to previous case law, features of the patent specification must be linked to a specific technical purpose. With the present leading decision Schlossgehäuse, the BGH has now summarised this case law with two clear guiding principles:

(a) An inventive step cannot be based on a feature that is an arbitrary selection from several possibilities detached from a specific technical purpose (confirmation of BGH, judgment of 22 May 2007 - X ZR 56/03, GRUR 2008, 56 para. 25 - Injizierbarer Mikroschaum; judgment of 27 November 2018 - X ZR 41/17, para. 46).

b) Special advantages associated with a feature can only be used to establish an inventive step if they are disclosed in the patent specification or are recognisable to a person skilled in the art (confirmation of BGH, judgement of 27 November 2018 - X ZR 41/17, para. 46).

BGH explanations on technical effect

Purpose and function specifications in a subject-matter claim do not regularly limit its subject-matter to the specified purpose or function, explained the BGH.
They regularly only define the subject matter protected by the patent as being designed in such a way that it can be used for the stated purpose or fulfil the stated function in addition to fulfilling the other physical and spatial features.

It must therefore be objectively suitable to fulfil the purpose or function. Even with such a concretisation, the claim directed to a device remains a substantive claim. It does not depend on the actual use of an item, nor what use it serves.

Which technical effects are to be taken into account

So which technical effects are to be taken into account when examining inventive step and which, if any, are not?

In short, all features with which a concrete, specific purpose is associated are to be taken into account.
Also important is the aspect that this purpose and functional details must be disclosed in in the patent filed. If these features existed objectively at the time of filing, but are recognisable to experts only in retrospect or are made accessible, such features are not to be taken into account for the inventive step.

The precise drafting of a patent is essential for successful patent protection. Our patent law firm is experienced in this.
Please contact us in any questions about patent protection or drafting, by telephone on +49 (0)69 69 59 60-0 or

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