Improvements and modifications occur regularly throughout a product's lifecycle. In some cases, a desire may arise to obtain patent protection over such developments. However, particularly at later stages in the lifecycle, complications can arise due to the nature of an organisation's own patent portfolio.

Australian law provides a useful mechanism for managing such complications: patents of addition. In overview, where a patent or patent application claims patent of addition status, there is scope to circumvent inventive step objections raised based on one's own patent portfolio. Such status can be claimed at any stage during the pendency of an application, and even after the grant of a patent (although the procedure is slightly more complicated). In this manner, addition status can be helpful in overcoming objections raised during prosecution, and for strengthening granted rights where enforcement proceedings are foreseeable.

Australian law describes a patent of addition in terms of requiring an improvement or modification to the "invention" of the parent application. In practice, the general test is effectively the same as for unity of invention. That is, were the claims of a patent of addition included in the parent application, no unity of invention objection should arise. This does not necessarily mean that the patent of addition must have narrower claims than the parent; simply that there should generally be a common inventive feature.

Other than the modified inventive step requirements, other general principles of validity apply as per usual. It is important to note that the priority date of a patent of addition is typically the date of filing, and there is no protection for novelty against publications or disclosures before that date, including prior publication by the disclosure of the parent application.  Additionally, the patent of addition shares the same term as its parent application.

It should also be noted that there is scope to amend a pending application to claim divisional status, provided the parent application remains pending, or provided the relevant filing date requirements for divisional applications are met at the time of filing the later pending application. This has a similar effect in terms of avoiding inventive step objections in light of one's own patent portfolio, and can have additional advantages in terms of flexibility.

These and other artefacts of Australian law can be a useful part of strategic portfolio management; and this is of course an area with which Shelston IP is well positioned to advise.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.