Tuesday, 23 November 2010

T 1989/08 – A Firm Belief

This decision also contains some interesting statements on prejudice.

[4.3] The Respondent asserts that a prejudice against varying additive concentration in the fuel would dissuade the skilled person from following any of the above paths. As explained [in the patent specification …] complex on-board dosing control is necessary to avoid overdosing which would deplete stored additive, but also lead to an increased ash burden in the Diesel particular filter (DPF).

[4.3.1] The Board finds that such a prejudice has not been conclusively proven.

In the jurisprudence a technical prejudice in a particular field is generally held to relate to an opinion or preconceived idea widely or universally held by experts in the field, see the Case Law of the Boards of Appeal, 5th edition, 2006 (CLBA hereinafter), I.D.9.2, page 161, final paragraph, and the case law cited therein.

To demonstrate prejudice requires a high standard of proof, as is evident from the immediately following paragraphs of the cited section of the CLBA. Thus, expression of the prejudice in standard works or a textbook is normally required, raising the level of proof close to that needed for proving common general knowledge. It is for example not enough that the opinion or idea is held by a limited number of individuals or that it is a prevalent view within a given firm, however large.

[4.3.2] Including evidence subsequently filed in the appeal procedure, all the evidence offered in support of the alleged prejudice, amounts to no more than 10 documents, all of which are either specialist papers or patents. This small number of publications intended for a select readership in the field is in itself a tenuous basis for asserting prejudice.

[4.3.3] Importantly, none of these documents expressly indicates that variation in additive concentration should be avoided. D9, which is given special significance in proving prejudice, only instructs avoiding additive contamination in the fuel in the main tank, as does D10. Both publications, the Board notes, share an author (Wiedemann) and originate in the same firm (Volkswagenwerk AG). Even if D9 and D10 had expressed the alleged belief, that would be a belief held in only one firm, not one prevalent across the whole breadth of the vehicle industry.

[4.3.4] Moreover, some of the evidence contradicts the alleged prejudice. D10 […] discusses a system with constant additive dosing rate (3ml/h) into the supply line. Fuel is supplied from a separate tank within the fuel tank to which excess additive rich fuel is again returned. Fuel is topped up from the remaining part of the tank to meet demand, whereas flow in the opposite direction is prevented to keep the fuel in the main tank pure. It is clear that depending on the engine operating conditions additive concentration in the separate tank (and supply and return lines) must fluctuate: low return of additive rich fuel means greater top-up with pure fuel which will decrease additive content, while high return means less top-up resulting in an increase in additive content. This is similar to the fluctuations described in the patent specification […], with the difference that the relative size of the separate chamber to the tank imposes greater limits on the amount of fluctuation.

[4.3.5] Likewise, D1, as discussed previously, generally regards the variation of the concentration of a fuel additive in the fuel to be advantageous, in particular in stop-and-go operation, with the concentration varying between a low value for high fuel consumption and a high value for low consumption. D1 may not mention catalytic additives for DPF regeneration, but its teaching is of general scope that applies to a wide range of additives independent of their purpose. Such a teaching surely inclines the skilled person towards, rather than away from a variation of additive concentration.

[4.3.6] If any common opinion does emerge from the various citations it most likely relates to dosing at optimum levels, high enough to ensure efficient and regular DPF regeneration in all operating conditions but not so high as to consume too much additive and/or saturate the DPF […]. This does not exclude variations in additive concentration, nor does it bar the skilled person continuing along any of the obvious paths described above. Mindful of such optimum dosing he will adjust various parameters - for example in the course of routine tests or trial and error - to ensure that he does not exceed optimum levels. This appears similar to the way the patent itself doses at a rate fixed at “a mean value between that ideally required for maximum and minimum fuel flows” […].

[4.4] In the light of the above the Board concludes that the dosing process defined in claim 1 of the main request lacks inventive step contrary to A 52(1) in combination with A 56.

Should you wish to download the whole decision, just click here.