This is one of two related articles on aspects of prior claiming. Prior claiming was a ground of invalidity under the Patents Act 1952 (1952 Act). It prevented grant of a patent claiming subject matter already claimed by another patent. Prior claiming was superseded by the broader concept of “whole of contents” novelty upon commencement of the Patents Act 1990 (1990 Act). Our related article questions the judicial authority suggesting prior claiming is no longer available to challenge patents filed under the 1952 Act. This article concerns the potential application of prior claiming case law to the current concept of “whole of contents” novelty.

The ground of prior claiming

Section 100(1)(f) of the 1952 Act provided that:

A standard patent may be revoked, either wholly or in so far as it relates to any claim of the complete specification, and a petty patent may be revoked, on one or more of the following grounds, but on no other ground:

(f)  that the invention, so far as claimed in any claim of the complete specification or in the claim of the petty patent specification, as the case may be, is the subject of a valid claim of earlier priority date contained in the complete specification of a standard patent or in the petty patent specification of a petty patent;…

The analysis conducted for prior claiming was similar in concept to the law in respect of interference actions as conducted before the US Patent and Trademark Office. However, the concept of “first to invent” did not apply – rather it was always clear as to which patent had precedence over the first.

The principle question posed in a “prior claiming” analysis was whether the claims of a patent are for the same invention as claimed by a previous registered patent. Mere verbal distinctions or variations in drafting would not prevent claims being for the same invention, the question being whether “… there can be read into an associated claim on a fair construction thereof a combination of integers which is in substance the same combination as may likewise fairly be read into another claim of different date …” 1  In other words, the approach is purposive in nature with the courts seeking to determine whether any apparent difference between the two claims was real or merely cosmetic.

In practice, for most technologies, unless the two claims were virtually identical, it was difficult to establish prior claiming.  However, in the case of chemical patents the situation was different.  As set out in the 5th edition of Blanco White:2

“In the chemical field, independent contemporaneous invention is not uncommon, whilst the extremely simple nature of claims to a chemical class of compounds means where inventions do cover the same subject-matter it is likely in chemical class cases that claims to them will in part coincide.”

(The authors of this article note, as an aside, that although claims to a class of chemical compounds may appear ‘extremely simple’, drafting such claims in a manner that provides sufficient fall-back positions and flexibility to deal with adventitious and/or unpublished prior art disclosures while maintaining the broadest protection possible is not a trivial undertaking.)

The most common, and most successful, approach to overcome a prior claiming objection was to establish that the claim of the later filed patent was a valid selection over the claims of the first patent.

A broad claim which encompasses a narrower later claim will prior claim that later claim unless the additional features in the narrower claim have some significance or importance to the invention, eg where the narrower claim is to a different combination and the narrower claim constitutes a selection over the earlier claim.3

In the Ethyl Corp case4 Graham J suggested that where the earlier claim is broad and includes within it the area covered by the later claims, a useful test for determining whether or not prior claiming has been made out is one similar to that applied in assessing the validity of a selection patent. If the later claim is properly to be regarded as selection from the earlier claims, remembering of course that it must be a selection hypothesis because the prior document was not known at the date of claiming, then the later claim should be upheld. If it merely amounts to reclaiming part of the earlier field then it should not be permitted.

A valid selection requires:

  1. the selection must be based on some substantial advantage gained or avoided;
  2. all members of the selected group mush possess the advantage;
  3. the selection must be in respect of a quality of a special character which may be fairly said to be peculiar to the selected group; and
  4. the selection must be defined in clear terms.5

In a number of respects, this approach reflects the “unexpected results” approach to determining a lack of obviousness in US Patent Law.

While there have been attempts to use the concept of “selection patents” in dealing with the more straightforward ground of anticipation by a published document this has never received whole-hearted judicial consent and the courts have generally fallen back to the established principles of novelty (see Markush claims under Australian patent practice).  This may well be because the courts have recognised the concept of selection patents is more applicable to a prior claiming situation where the overlap of two claims with different priority dates is at issue.

“Whole of contents” novelty

“Prior claiming” was replaced by the concept of “whole of contents” novelty upon commencement of the 1990 Act.  “Whole of content” was introduced by including the following definition of the prior art base which would be assessed by a Court in determining the ground of novelty.

When determining novelty under the 1990 Act the “prior art base” includes information contained in a published specification filed in respect of a complete application where:

  1. if the information was the subject of a claim of the specification it would have had an earlier priority date than the claim under consideration; and
  2. the specification was published after the priority date of the claim under consideration; and
  3. the information was contained in the specification on its filing date and when it was published.6

The requirement for “whole of contents” novelty was introduced to expand the ground of prior claiming, which was considered to be unsatisfactory in practice and too narrow.The test was expanded so that the entire specification of the earlier filed patent was considered rather than just the granted claims. Initially, “whole of contents” novelty was approached quite differently to prior claiming. The approach was more reflective of a traditional novelty attack and similar to the approach taken to “whole of contents” novelty in Europe.  As a result, it could be argued that prior claiming case law was irrelevant to “whole of contents” novelty and the statement that “There is no equivalent of s 100(1)(f) of the 1952 Act as a ground of revocation in s 138(3)8 was certainly made in this context.

However, “whole of contents” novelty case law has developed in a way that brings that ground significantly closer to the concept of prior claiming. Establishing “whole of contents” lack of novelty now requires showing invalidity over either a claim of the earlier filed patent or a notional claim of the earlier filed patent. The notional claim is a claim that the earlier filed patent could have included because there is appropriate basis for that claim in the earlier filed patent. The most recent Federal Court comment on this ground is in the Danisco case:9

A “whole of contents” objection under s 7(1)(c) and para (b)(ii) of the definition of “prior art base” in the Dictionary in Sch 1 to the Act attracts additional considerations. The usual rules as to clarity of disclosure to the skilled addressee apply but, in addition, it must be possible to draft a notional claim (assuming there is not an actual claim to the relevant subject matter) that is fairly based on the disclosure of the prior specification relied upon (E I Du Pont de Nemours & Co v ICI Chemicals & Polymers Ltd (2005) 66 IPR 462 at [80]–[84] per Emmett J)……

The introduction of s 7(1) and the definition of “prior art base” into the Act expanded the concept of novelty to include some aspects of prior claiming, such that the doctrine of prior claiming was subsumed into novelty (see Alcatel NV v Cmr of Patents (1996) 68 FCR 8 at 10–11). The intention, as revealed in the IPAC report (Industrial Property Advisory Committee, Patents, Innovation and Competition in Australia (Industrial Property Advisory Committee, Canberra, 1984)) to which Burchett J referred in Alcatel, was to introduce a “whole of contents” approach such that novelty was judged by reference to the whole of a specification filed but not published before the priority date and not just by the claims of that specification. The IPAC Report refers at 7.3 to “any disclosure contained in an earlier specification”. That does not assist in an understanding of the scope of “information” in para (b)(ii) of the definition of “prior art base”. It may refer to the disclosure of the whole of the specification or, as Novozymes has accepted, require identified information, such as the passages relied on by Novozymes below.

The fact that the ground of “whole of contents” novelty is now significantly closer to the previous ground of prior claiming raises some interesting possibilities.  It is possible that the principles underlining the case law relating to prior claiming will become more relevant in considering the ground of “whole of contents” novelty as these principles are directed to a comparison of claim scope.  As a consequence, the established principles relating to “valid selections” should also become more relevant, and subject to judicial consideration, particularly in the chemical field.