The recent decision in BlueScope v Dongkuk reinforces the importance of those applying for and challenging patents in Australia considering the 'best method' requirement, as a shield or sword respectively.

Key takeouts

At the time of filing a complete patent application in Australia (which is often the filing of a PCT application designating Australia), applicants should consider whether they have disclosed the best method of working the invention in their knowledge (including corporate knowledge) as at that date. If the best method is not disclosed, the patent application may be refused grant or, if granted, later revoked.

Those seeking to invalidate Australian patents should consider whether they can establish that the specification does not disclose the best method known to the applicant at the filing date. There is no equivalent ground of revocation for European or US patents.

Here BlueScope's patents were held to be invalid because Dongkuk established that at the filing date, BlueScope knew that 'special operating measures' were essential to the best method of performing the invention, but BlueScope had not disclosed what those measures were.

Although not common, Australian patents will be held invalid for failing to disclose the 'best method' of performing the invention under section 40(2)(aa) of the Patents Act, as demonstrated in the Federal Court's decision in BlueScope v Dongkuk (No 2) [2019] FCA 2117.

Australian patent specifications must disclose the 'best method'

The recent decision in BlueScope v Dongkuk reinforces the importance of those applying for and challenging patents in Australia considering the 'best method' requirement, as a shield or sword respectively. Such considerations have the potential to be overlooked, given best method has no equivalent in the European Patent Convention, is not a ground of revocation in the US, and is typically considered a minor ground of invalidity in Australia.

An Australian patent can be refused or revoked in its entirety on the ground that the specification does not disclose the 'best method' known to the applicant of performing the invention (under s 40(2)(aa) of the Patents Act 1990, previously s 40(2)(a)). The purpose of the requirement is to allow the public the full benefit of that invention when the monopoly expires. What must be disclosed will depend on the nature of the invention, as described in the whole of the specification.

In 2016, we published an update on the Full Federal Court decision in Servier v Apotex, the leading authority on best method.

Subsequently, in GSK v Apotex and now BlueScope v Dongkuk, Beach J has reiterated the following:

  1. The skilled addressee must be able to arrive at the best method known to the patent applicant including by some routine experimentation, but without the need for ingenuity or undue experimentation.
  2. A patent applicant need not disclose details of the method which would be well-known and understood by the skilled addressee such as well-known analytical agents, commonly used methods, well-known terms of art, or a description of machinery in standard use.
  3. A complete specification must disclose each essential element or feature for performing the invention, even if a skilled addressee would know or readily ascertain that element.
  4. Where the best performance of the invention requires a step that is omitted by the complete specification, even if it could be readily ascertained by a skilled addressee, it will not meet the best method requirement.
  5. If the skilled addressee is left to make a choice as to what analytical agent to use, what commonly used method to use or what machinery to use, or is left in doubt as to what a term means, the best method will not have been described if that choice or uncertainty affects the performance of that method.

However, the patent applicant does not need to expressly identify the best method in the patent specification. For example, the best method might be included as one of several examples without being identified as the best.

In order to succeed in a revocation action, a person challenging a patent needs to establish the patent applicant's relevant subjective state of mind with respect to its knowledge of the best method of performing the invention at the date of filing the complete application.

BlueScope v Dongkuk decision

In summary, in BlueScope v Dongkuk Beach J:

  • Rejected BlueScope’s infringement case, even if the patents had been valid, because of issues with the experimental evidence presented by BlueScope;
  • Held the patents to be invalid because the specifications failed to disclose the best method known to BlueScope at the filing date; and
  • Rejected BlueScope’s application to amend the patent specification.

While the overall result is a resounding win for Dongkuk, it is worth noting that Beach J rejected six of the seven grounds of invalidity raised by Dongkuk: lack of novelty, inventive step, full description, clarity, fair basis, and false suggestion. This highlights the significance of the best method ground in certain cases.

At the time of writing, BlueScope has not yet filed an appeal, though it remains open to them to do so.

BlueScope's failure to disclose its 'special operational measures'

BlueScope owned two patents relating to steel strips with a corrosion-resistant alloy coating, and a 'hot dip' coating method for manufacturing them. One of the specifications (the 257 patent) disclosed the need to apply 'special operational measures' in the coating process, in order to control 'coating thickness variations'. Dongkuk argued that BlueScope failed to disclose the best method because it had not disclosed the specific 'special operational measures' that were required.

BlueScope conceded that at the filing date, it knew of four operating measures to control short range coating thickness variation, but argued that these would have been known to the skilled addressee, and involved routine adjustments to the manufacturing process that could be implemented without undue burden.

After reviewing the specification as a whole, Beach J said that the nature of the invention described and claimed in the specification was to ensure that the short range coating thickness variations were controlled to a maximum variation of 40% in an 5 mm diameter. The specification disclosed that in order for that to be achieved 'special operational measures' had to be applied. Accordingly, BlueScope was under an obligation to disclose the 'special operational measures' known to it at the filing date to control short term coating variation.

Justice Beach found that there were four reasons demonstrating that BlueScope failed to disclose the best method known to it:

  1. A skilled addressee would not understand what was meant by 'special operational measures' in the context of the specification.
  2. Even if the best operating measures formed part of the CGK, the skilled addressee would not understand that those measures were being referred to. The skilled addressee would think the use of the word 'special' referred to operating measures beyond those known to them.
  3. There were many different operating measures known by the skilled addressee at the filing date to control variations in coating thickness, but the best method involved the use of four of these operating measures together, as known to BlueScope. Even if the skilled addressee was to construe 'special operational measures' as 'ordinary operational measures' they would still not know which of those operating measures were the best to perform the invention.
  4. The particular stabilisers used in the best method known to BlueScope did not form part of the CGK at the filing date. In the circumstances, the skilled addressee would not understand the reference to 'special operational measures' to include these stabilisers.

Justice Beach consequently found that this lack of disclosure of the best method also invalidated claims of BlueScope's second patent (the 258 patent) notwithstanding that it did not use the expression 'special operational measures'.

BlueScope not permitted to amend

In anticipation of a potential finding against it on best method, BlueScope had applied to amend the specification to introduce a description of the 'special operational measures'. Beach J said that the amendments were technically allowable as they did not broaden the scope of the claims, which was the only restriction applicable in 2009 (under the current Patents Act, an amendment must not introduce matter that extends beyond that disclosed in the specification at the time of filing).

However, Beach J exercised the Court's discretion to refuse the amendments, after making the following findings:

  1. BlueScope failed to provide a full and frank disclosure of the reasons for seeking an amendment and explaining any delay in seeking the amendment. BlueScope failed to disclose the examination reports for its corresponding US patent application which included one of the objections which put BlueScope on constructive notice of the need to amend the specification. BlueScope submitted that that was inadvertent because the objections were prior art based and not related to sufficiency or enablement.
  2. BlueScope gained an unfair advantage by failing to disclose the best method to the public at the filing date – it had secretly applied and optimised the method from 2009 to 2013, and used it commercially from 2013. BlueScope also obtained an unfair advantage by threatening Dongkuk with infringement proceedings on the unamended patent which BlueScope knew or ought to have known was invalid.
  3. There was an unreasonable delay in seeking the amendment. The prosecution of the corresponding patent applications in Australia and a number of other countries had raised objections regarding the application, and referred to the term 'special operational measures'. BlueScope had constructive knowledge of the need to amend well before it did so and simply made a calculated decision to take its chances with the disclosure it had made, whilst simultaneously benefitting commercially from the best method to the detriment of the public.