Essential Inventive Step Reminders (T 686/18)

Essential Inventive Step Reminders (T 686/18)

The headlines

A recent Board of Appeal decision at the European Patent Office (EPO) has reaffirmed a key practice point in the demonstration of inventive step when drafting and prosecuting patent applications in Europe: the objective technical problem shall not contain any pointer to the solution.
In its decision, the Board expressed a need to reformulate the objective technical problem set out in the application as filed as it contained a pointer to the claimed solution.  The Board continued to use the patent as guidance for the formulation of a new problem and found this problem to be solved by non-obvious means, concluding that the subject matter was inventive.
This case serves as a reminder to applicants of some practice points to bear in mind when drafting: 

  • Practice point 1: applicants should not point to any element of the solution when devising the problem in the application; and  

  • Practice point 2: applicants should include a number of problems in the application when drafting, ensuring an examiner has access to information which can guide their reformulation of the problem.


The detail

After the determination of the closest prior art, the formulation of the objective technical problem forms the second stage of the EPO’s problem-solution approach to assessing inventive step. 

In the present case (T 686/18), the technology of the patent concerned the creation of foamed polymers by the forming of cavities using expanded hollow microspheres or “microballoons”.  Microballoons have their own polymer shell, inside which is a liquid which expands upon the application of heat to form a cavity.  In the forming of such polymers, air can cause additional holes which are not made by the expansion of the microballoons and these holes are known as “voids”.  Claim 15 of the patent effectively stipulated that the proportion of voids formed without the use of microballoons is not more than 2% by volume.
The patent was opposed, and an interlocutory decision was made during the opposition proceedings that the requirements of the EPC for inventive step were met by the patent.  The opposition division’s decision was appealed and the appellant requested that the patent be revoked in its entirety.
Below, I have focussed on the Board’s approach to considering inventive step of claim 15 of the patent in suit. 

Inventive Step as considered by The Board in T686/18 

Claim 15 differed from the closest prior art document in that the proportion of caverns without their own polymer shell (voids) was stipulated to be not more than 2% by volume. 

The Board noted that the problem posed in the patent should be assumed to be correct initially, but that in some cases such a problem may need to be reformulated.  The reasons for reformulation of the problem are as follows:

  1. Where the problem is not solved by the claimed subject matter;

  2. Where the problem has already been solved in the closest prior art; or

  3. Where the problem includes possible solutions or partial anticipation of the solution, since this would inevitably lead to a retrospective view of inventive step.

The appellant tried to dispute the legitimacy of claim 15, arguing that it merely stated a result to be achieved in accordance with paragraph [0008] of the patent in suit. This paragraph reads:

The object of the invention is to provide a foamed polymer mass [...] which is free from such cavities that are not created by microballoons ..."

In making this argument, the appellant may have highlighted to the Board the shortcomings of the formulation of the problem in assessing inventive step in the present case.  The Board disagreed with the assertion from the appellant but noted that a problem based on paragraph [0008] – which indicates the desire for the avoidance of additional cavities (voids) produced without the use of microballoons – should be ruled out objectively on the basis that it provided a pointer to the solution. 

The respondent requested that the Board consider paragraphs [0003] and [0055] of the patent in suit which explained the existence of voids in such polymers and the properties exhibited by foamed material made using microballoons when the number of voids is kept small. As a result, the Board recognised that a new problem should be formulated as how to achieve such properties, since this formulation did not give an indication of how to solve such a problem.

Claim 15 was adjudged to have solved this problem by declaring a maximum of 2% by volume of void cavities.  Due to none of the prior art working in this range, the Board came to the decision that such a solution was not obvious in the present case.

Practice points: pave a predictable path

This decision reminds applicants that the direction of prosecution is steered at the drafting stage. A well-devised problem at the drafting stage can go some way to ensuring that the road to grant may take a predictable path. 
Importantly, reformulation of the problem posed at the drafting stage can be somewhat mitigated by outlining the present drawbacks and hurdles to be overcome in the specification before introducing any elements of the solution. Putting some level of separation between the description of the present technological landscape and the proposed developments in the solution will help to avoid any reference to the solution when setting up the problem. This gives the problem the best chance at withstanding examiner scrutiny. 

Practice points: navigating a bump in the road

In practice, prosecution of the application is often a bumpy road. There are obstacles which could arise during prosecution in the form of prior art. The existence of certain prior art documents may cause the originally posed problem to become unsuitable.  
In this event, it may be useful to have included information in the specification from which a new objective technical problem can be formulated.
The EPO Guidelines for Examination state:
As a matter of principle any effect provided by the invention may be used as a basis for the reformulation of the technical problem, as long as said effect is derivable from the application as filed”.
Therefore, try to include problems associated with some of these effects without disrupting the narrative of the application.  If the examiner formulates the problem incorrectly, propose a new problem during prosecution which is solved by features having these effects, being careful to avoid inclusion of any pointers to these features in the problem.

Final thoughts:

The Board’s decision highlights the importance of ensuring that the problem does not contain any element of the solution.  If the problem falls foul of this guidance, the obviousness of the solution may be considered with the impermissible use of hindsight and the assessment of inventive step will not be a fair one.  
Encouragingly, the EPO ensured that the problem was correctly formulated in the present case such that a fair assessment of inventive step could take place. 

If you would like to have a word with Jonathan about this article, or wish to find out more about this topic,  feel free to contact him, or get in touch with your usual Kilburn & Strode advisor.

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