The Federal Court has recently heard a claim for revocation of two Australian patents on the grounds that the patent specifications did not disclose the best method known to the inventor of performing the claimed invention.  Justice Bennett's decision highlights the difficulties in revoking a patent for failing to disclose the best method of performing an invention.  Furthermore, the decision provides guidance on the matters to be established for such a claim to be successful.

Buono-Net's invalidity claim: that the patent specifications did not disclose the invention in sufficient detail

Buono-Net Australia Pty Ltd applied for a summary judgement seeking revocation of the standard and innovation patent Nos. 2006226731 and 2007100339 owned by Expo-Net Danmark A/S on the basis that neither specification disclosed "the best method known to the applicant of performing the invention".  In general terms, patent laws require inventors to provide enough information in the patent specification that allows the invention to be put into effect without additional inventive endeavour.  Buono-Net thus alleged that neither patent satisfied this requirement in accordance with Section 40(2)(a) of the Patents Act 1990.

Justice Bennett's findings

At the outset, Justice Bennett identified that for the application to be successful, it was necessary to:

  1. understand what the invention is; and
  2. determine that there was a better method known to the applicant at the date of filing the patent than the one described in the specification.

Buono-Net's application was unsuccessful because Justice Bennett held the view that Expo-Net had a reasonable prospect of defending the claim for revocation of the patents for failure to comply with the requirements of Section 40(2)(a).  There were two reasons that Justice Bennett held this view, as discussed below.

Buono-Net's conflicting grounds of invalidity

Firstly, Buono-Net also had a cross-claim for revocation, presumably of the standard patent, on the basis that the invention lacked inventive step (which was not part of the hearing).  To this end, Buono Net submitted evidence that the invention was obvious to a person skilled in the art in light of the common general knowledge at the priority date.  Indeed, there is a tension between alleging that the claimed invention lacks inventive step because it could be achieved by a matter of routine, and simultaneously alleging that the specification fails to disclose the best method because it omits information necessary for a person skilled in the art to be able to work the claimed invention.

Conflicting evidence left sufficient doubt

The second reason involves the evidence of the inventor relating to his experiments conducted to bring the invention into effect.  The invention, as claimed in the patents, relates to a method of producing a product that, significantly, uses a "foaming additive" that expands during the process.  During the experiments, the inventor had trialled at least five different foaming additives in controlled conditions; two additives were considered workable and the remaining additives were not.

Buono-Net contended that the failure in the specification to disclose the foaming additives that did not work in the experimental trials constitutes a failure to disclose the best method known to the applicant.  However, there was also evidence that the behaviour of a foaming additive is at least partly dependent on variables (such as temperature and pressure) to which the additive is subjected to during the process.  This means that in the experimental conditions some additives would not achieve the desired result, but in other conditions they may.  Justice Bennett concluded that the invention involves the interaction of integers, and that routine adjustment of variables would be required in order to work the invention.  Accordingly, the inventor's evidence that certain foaming additives did not provide the desired result did not unequivocally support the contention that the specification did not disclose the best method enabling a person of ordinary skill in the art to work the invention.

It follows that Expo-Net has a reasonable prospect of defending the claim that the applicant knew of better method for performing the invention than the one described in the specification as filed.

Substantive hearing to follow

The decision highlights the difficulties in revoking a patent for failing to disclose the best method of performing the invention.  This ground of revocation can still be pursued by Buono-Net at the substantive hearing.  The outcome of that hearing may help answer the question of how much information is necessary to disclose the best method of performing an invention.