Small matter, big problem: the story of the average sized particle

Now where the deuce did that nanomouse go?
The IPKat has frequently been preoccupied with interesting questions that have no obvious answer. Classic examples include "how long is a piece of string?", "where do celebrities go when they want some privacy?" and "why aren't all the Court of Justice opinions and decisions translated into English?" Today he has been pondering a new question, thanks to a decision of a Technical Board of Appeal of the European Patent Office: "how big is an average sized particle?" This was the issue at the heart of T-1819/07 Nanosized catalyst/ GENERAL ELECTRIC, decided on 15 March 2011 but only now disturbing the Kat's grey cells.

Without going into too much detail, it appears that the claims in General Electric's patent application referred to a
"copper catalyst precursor selected from the group consisting of copper metal, copper (I) oxide, copper (II) oxide, copper (I) chloride, copper (II) chloride, copper (I) carboxylates, copper (II) carboxylates, other copper salts, and mixtures thereof, having an average particle size from about 0.1 to about 600 nanometers".
This would have been fine for the Kat, because he's not what the Americans call the PHOSITA (Pussycat having ordinary skill in the art) it's all the same to him where in the range of 0.1 to about 600 nanometers this average particle size happened to be.  However, since the claims did not unambiguously state either the type of average involved (volume, surface, number) or a method for determining it, the examiner was none too impressed and refused the application.

Dismissing GE's appeal, the Technical Board affirmed that the claims were unpatentable for lack of clarity. It rejected the argument that the necessary clarity was provided by a statement in the specification that the preferred embodiment was to use particles prepared according to the method of an identified co-pending patent application, which did contain a description of a method of measuring size. This was because the terms of that reference, relating only to the method of making the particles, did not make the disclosure of the method of measuring the particles' size part of the disclosure of the present application.

Wonders the IPKat. is this one of those miserable cases where we all really know what the applicant means but have to penalise him for not having clearly and explicitly said it? Or is it a case of a crafty applicant trying to gain a little extra edge over anyone putting the invention into effect by being less than specific? Merpel says,   I think this case is only being discussed here because it's about a Katalyst.

Nano stuff here
Nani stuff here
Nana stuff here
Small matter, big problem: the story of the average sized particle Small matter, big problem: the story of the average sized particle Reviewed by Jeremy on Monday, May 23, 2011 Rating: 5


  1. The EPO guidelines for examination clearly set out what is required when parameters are in a claim. Most applications (and unfortunately many granted patents) do not comply with these requirements.
    Although some might think that the EPO is too strict when considering clarity or sufficiency in respect of parameters, national patent judges are quite happy when they do not have to rely so heavily on the parties' experts telling them how the parameter should be understood.

  2. Whilst the average size of your typical football, apple or other normally spherical object is usually self evident when you get down to thousandths of the wavelength of light (0.1nm) all sorts of weird and wonderful measurement effects occur and depending upon the average chosen all sorts of numbers can be conjured up. The moral of the tale here is presumably to make sure that the attorney drafting the work knows the science?

    However, common sense also goes a long way and our football analogy can be helpful, the informed attorney will immediately spot the size of the range 0.1 to 600. So how effective would it be if you defined the football having a size range from 0.1cm to 600cm, by analogy?

  3. "You know what I mean" is simply not enough to comply with Art. 84 EPC. Put it in the claim!

    If that's somehow not possible (anymore... i.e. after filing), that's not the EPO's fault.

    Having an attorney that really understands the technical detail and is able to put this into precise words can make all the difference. In the computer field it is all too common to see claims use the same term for entirely different concepts. For example, a claim might use "the program" to refer to source code, object code, an executing process in memory, etc. Such abuse of language is fine for everyday purposes, but not for defining an invention with an eye to getting patent protection. Often representatives aren't even aware of such distinctions. It is not only the president of the EPO that has difficulties with logic as discussed in G 3/08, point 11.2.3.

  4. Given that the atomic radius of a copper atom is 0.128nm, the size range seems to me to be not just difficult to measure but in fact impossible.


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