The Australian Patent Office’s recent decision in Compac Technologies Limited v MAF Agrobotic [2025] APO 37 serves as a timely reminder that patent applicants must fully disclose the best method known to them of performing their invention when filing an Australian patent application.
The case, involving technology for sorting fruit, provides a fresh opportunity to revisit the “best-method” requirement and how easily a patent application can turn sour if key implementation details are left out.
The Best Method Requirement
Section 40(2)(aa) of the Patents Act 1990 (Cth) requires a complete specification to “disclose the best method known to the applicant of performing the invention.”
This provision ensures that a patentee gives the public the full benefit of their invention in exchange for the exclusive rights granted by a patent. The disclosure must enable a skilled person to perform the invention in the best way known to the applicant at the time of filing, not just a workable embodiment.
A broad description of the invention’s concept or generic functionality will not suffice. Applicants must include the practical details, such as specific parameters, materials, configurations or operating conditions, that make their version of the invention work optimally. The best-method requirement applies as at the filing date and cannot be cured by later amendment if the information was not originally included.
The Decision
MAF Agrobotic’s patent application (Australian Patent Application No. 2018226589) related to a fruit and vegetable optical analysis and sorting device that used a colour CMOS camera to capture images in both visible and infrared ranges.
The opponent, Compac Technologies, asserted, amongst a number of grounds, that the specification failed to disclose the best method known to MAF at the priority date. The Delegate agreed concluding that while the specification described the concept of using a colour camera without an infrared cut-off filter, it did not explain in sufficient detail how that setup was achieved or configured, particularly in relation to the operation of Figure 3 of the specification and the associated imaging parameters. Despite opportunities to clarify through evidence, MAF allegedly provided no explanation of the figure or practical details demonstrating how the system was implemented.
The Delegate observed:
“There is no evidence from the applicant explaining the nature and content of Figure 3 or how the system was actually configured in practice. The specification, as filed, lacks the information necessary to perform the invention in the best way known to the applicant.”
The Delegate also reaffirmed the legal principle underpinning section 40(2)(aa), noting that the obligation “is not satisfied by describing a generally workable method.” What must be disclosed is “…the particular method which the applicant recognises as being the best at the time of filing.”
The Delegate concluded that “the complete specification does not disclose the best method known to the applicant of performing the invention,” a deficiency that could not be overcome by amendment. The opposition succeeded and the application was refused, with costs awarded against MAF Agrobotic.
Remedy and Next Steps
Once a complete patent application has been filed without disclosing the best method, that defect cannot be rectified within the same application. The omission goes to the sufficiency of the original disclosure, and no post-filing amendment can add information that was not present at the time of filing.
However, there may still be practical options to preserve protection. In this case, MAF Agrobotic had already filed a divisional application based on the refused parent. It remains open to file a further divisional application that includes new information disclosing the best method of performing the invention. This allows the applicant to capture the missing practical details, for example, the configuration and operation of the camera system, that were not included in the parent specification.
Including additional disclosure in a divisional application does not by itself affect the priority date of claims that remain fully supported by the original specification. The requirements for novelty and inventive step apply only to the claimed invention, so if the divisional claims are confined to what was already disclosed in the parent, the earlier priority date is preserved.
However, the Delegate all concluded that the missing camera details may give rise to a support issue under section 40(3). If the claims in a new divisional are amended to rely on this newly added disclosure in order to overcome that lack of support, those claims would no longer be entitled to the parent’s priority date. They would instead be examined for novelty and inventive step as at the divisional’s filing date.
Key Takeaway
This decision is a clear reminder that the best-method requirement remains alive and kicking under Australian patent law. A missing detail today could be the reason an application fails tomorrow. As the Delegate succinctly stated,
“The best-method requirement remains a fundamental element of the patent bargain.”
Before filing, applicants and attorneys should carefully review whether the specification truly reflects the best way known to perform the invention, not merely a way that works.
