The key issue

The key issue considered in this judgment was the criteria under which a single claim could be considered to define multiple forms of an invention, with each form of the invention attributed its own priority date.

When is this relevant?

This is relevant where:

  1. You file a complete/PCT application that includes multiple priority claims each with different dates, or
  2. Your complete/PCT application has a single priority claim, but substantive matter was added to your complete/PCT application on filing.


the claims in your complete/PCT application are based on a combination of features from these multiple disclosures.

What do I need to do if this situation applies to my complete/PCT application?

This case has again highlighted that careful and considered claim drafting is critical to the preparation of a patent application where the claims include a combination of features, each with different priority dates.

There are two key teachings from this case:

  1. If your claim combines features having different priority dates, then it is important to draft the claim in a manner which indicates that the claim defines clear alternatives, such as by including discrete and express selection steps that provide for different outcomes or products.
  2. Ensure fall-back dependent claims are included into your claim set “to split a composite claim into various forms of the invention so as to render each as a separate claim with its own priority date.”1


Nichia Corporation (“Nichia”) is the patentee of Australian patent 1997036355 filed 29 July 1997 directed to a light emitting device and display. Nichia filed Federal Court proceedings in June 2014 seeking an injunction to restrain Arrow from infringing claims 1 and 3 (dependent on claim 1) of Nichia’s patent, and claiming damages and an account of profits for infringement with regards to certain LED products manufactured by Everlight Electronics Co in Taiwan, and imported and sold by Arrow in Australia. Arrow counter-claimed, seeking revocation of claims 1 and 3 on various grounds.

Justice Yates ruled that as the priority date of claims 1 and 3 would impact on how Arrow challenged validity, that the threshold question to be determined separately was the priority date of claims 1 and 3.

The relevant portion of claim 1 reads:

“1.A light emitting device, including a light emitting component and a phosphor…

wherein … said phosphor contains a garnet fluorescent material including at least one element selected from the group consisting of Y, Lu, Sc, La, Gd and Sm, and at least one element selected from the group consisting of Al, Ga and In, and being activated with cerium.”

Claim 3 reads:

“3.A light emitting device according to claim 1, wherein the phosphor contains fluorescent material represented by a general formula (Re1-r,Smr)3(Al1-sGas)5O12:Ce, where 0≤r<1 and 0≤s≤1 and Re is at least one selected from Y and Gd.”

The issue of priority date has arisen as the selection of Lu, Sc, and In (as recited in claim 1) is not disclosed in any of the priority documents.

By way of background, Section 43(1) of the Patents Act (1990) states that each claim must have a priority date. Section 43(3) specifies that where a claim defines more than one form of an invention, then, for the purposes of determining the priority date of the claim, it must be treated as a separate claim for each form of the invention that is defined. Section 44(4) states that the priority date of a claim may be different from the priority date of any other claim in the specification.

Arrow submitted that:

  • The priority date of claim 1 is the filing date of the patent application (i.e. 29 July 1997) as the selection of Lu, Sc, and In was first disclosed on filing the PCT application.
  • Claim 3, when notionally re-written, includes all the limitations of claim 1 (even redundant limitations directed to the selection of Lu, Sc, and In - which are excluded from claim 3). Therefore, the priority date of claim 3 should be the same as claim 1, i.e. the filing date of 29 July 1997.
  • Claim 3 defines a single form of the invention and has no alternative roots of dependency (other than to claim 1), therefore Section 43(3) affording multiple priority dates to the claims does not apply.

Nichia disagreed on the basis that:

  • Claim 1 defines multiple forms of the invention. Each of those forms should be attributed an appropriate priority date. Thus, only the forms of the invention that include Lu, Sc, and In should be given the filing date of 29 July 1997. Other forms should be given an appropriate earlier priority date.
  • Claim 3 narrows the scope of claim 1 and acts to exclude the redundant subject matter of claim 1. That is, claim 3 relates to specific fluorescent material that does not include Lu, Sc, and In. As such, the priority date of claim 3 should be determined separately from that of claim 1.

Unsurprisingly, Justice Yates agreed with Nichia in respect of claim 3 stating that “I cannot see how claim 3 can be assigned a priority date based on selected combinations arising under claim 1 that are not within the scope of claim 3 itself.”2

It then fell to Justice Yates to determine whether claim 1 defined: (i) separate forms of an invention, or (ii) potential variants. The distinction being that Section 43(3) allows multiple priority dates only if the claims define separate forms of the invention.

What constitutes a separate form of the invention as opposed to a potential variant?

Justice Yates referred to the recent AstraZeneca v Apotex decision3 as providing guidance as to the type of claim that does not define multiple forms of the invention. In this decision, the Full Court emphasised that a key consideration was whether “by their terms” a claim allowed for alternatives. However, there is little Australian jurisprudence on how this applies and what sort of “terms” specifically allow for alternatives.

Justice Yates referred to UK case law as providing some guidance of the test to apply. This case law suggested that a claim provides clear alternatives if it includes a selection step that provides a different product. Justice Yates adopted this approach in concluding that: “claim 1 includes two discrete and express selection steps… providing for differently constituted phosphors, depending on the selections made and the combinations arrived at. I am satisfied that, by their terms, each of claims 1 and 3… provide for different forms of the invention.”4

Based on this it seems that a claim will likely be considered to define separate forms of the invention if:

  • there is a discrete and express selection step, and
  • the selection made in the discrete and express selection step provides for a different outcome or product.

Shaun McVicar