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Double patenting not a ground for revocation

9 minute read

Arbitron v Telecontrol Aktiengesellschaft [2010] FCA 302

Double patenting or double claiming, i.e., claiming the same invention as another patent with the same inventor(s) and priority date, is a ground of objection during Australian examination. The Federal Court of Australia has recently found that double patenting is not a ground for revocation under the Patents Act 1990 (Cth) (“the Act”), and that an erroneously granted patent can still remain on the Register of Patents.


Relevant Legislation and Office Practice

Under the Act, a standard patent cannot be granted, and an innovation patent [1] cannot be certified, by the Patent Office if the standard application or innovation patent claims an invention that is the same as an invention that is the subject of another patent, made by the same inventor, and having the same priority date (sections 64(2) and101B(6)).

It is therefore the practice of the Patent Office to object to double patenting, although the test applied in the past has been quite narrow. The test requires that the claims be of identical scope, and that the double patenting situation be so plainly evident that it is beyond reasonable argument.[2]

Following grant or certification of a patent, the grounds for revocation under the Act include only the following: (i) that the patentee is not entitled to the patent; (ii) that the invention is not a patentable invention (which includes being novel and inventive); (iii) that the patent, or an amendment, was made or obtained by fraud, false suggestion or misrepresentation; and (iv) that the patent specification does not comply with formal requirements such as clarity, sufficiency, fair basis, etc. (section 138(b)). There is no clear ground for revocation of a granted patent, or certified innovation patent, arising from a double patenting problem.
The Register of Patents is held by the Patent Office and records particulars of patents, such as details of grant and ownership. To have standing to initiate infringement proceedings, a patentee or exclusive licensee must be recorded in the Register.

Facts of the Case

Arbitron Inc. initiated proceedings against Telecontrol AG and AC Nielsen (Holdings) Pty Ltd for infringement of Australian Patent No. 747044 (“the Patent”). The Patent was granted based on a divisional application from what became Australian Patent No. 718227 (“the Parent Patent”) which was itself based on a divisional application from an International (PCT) application which became Australian Patent No. 678163 (“the Grandparent Patent”). The Patent relates to automatic recognition of widely disseminated audio signals, such as television and radio broadcast signals, using an electronic signature. In Court, Arbitron asserted that Telecontrol’s device infringed various claims of the Patent. The Telecontrol device is attached to a person’s wrist and detects ambient sounds. The device records audio signals to determine the broadcast material to which a person may have been listening, e.g., to automatically create audience surveys. The Patent has claims 1–4 that are similar to claims 17–20 of the Grandparent Patent. The relevant claims have the same inventors and claim the same priority date. Claim 1 of the Patent was amended to differ from claim 17 of the Grandparent Patent only by the removal of the letter “s” from the word “bands”, as shown below (with the “s” shown in square brackets):

1. A method of producing a signature characterizing an audio broadcast signal for use in broadcast signal recognition, comprising the steps of:

forming a plurality of frequency band values each representing portions of said audio broadcast signal within respective predetermined frequency band[s];

comparing each of a first group of said plurality of frequency band values with a respective one of a second group of said plurality of frequency band values representing portions of said audio broadcast signal within the same respective predetermined frequency band, each respective one of the second group of said plurality of frequency band values representing portions of said audio broadcast signal at least a part of which were broadcast prior to the portions of said audio broadcast signal represented by the corresponding one of said first group of said plurality of frequency band values; and

forming said signature based upon the comparisons of the first and second groups of said plurality of frequency band values.

Dependent claims 2 and 3 of the Patent differ from claims 18 and 19 of the Grandparent Patent by replacement of the term “a respective one of said predetermined frequency bands” with “a respective predetermined frequency band”. Independent system claim 4 of the Patent has equivalent amendments to those of claim 1.

The Decision

Double Patenting

Telecontrol asserted that the Patent was granted in contravention of the Act due to double patenting (under section 64(2)).
Arbitron argued that the invention of the Patent used the contribution of the audio signal from only one frequency band at a time in forming the audio signature, in contrast to that of the Grandparent Patent which used a plurality of frequency bands at a time. The Court presumed that the indefinite article “a” was unintentionally missing from claim 1, and that the author intended it to be included in the phrase “within a respective predetermined frequency band”, thus more clearly construing a difference between Patent claim 1 and Grandparent Patent claim 17.

The Court (by comparing sections 64(1) and 64(2) relating to double patenting) came to the view that the notion of “substantial identity” falls outside the notion that is conveyed by the phrase “the same”, but that just because claims are not literally identical, does not necessarily mean that they are not for the same invention, and that if differences in the wording are inconsequential, the claims may relate to the same invention.

The Court did not consider that the change in the Patent to a single frequency band was “material”, and held therefore that the invention was the same, and that grant of the Patent was prohibited under section 64(2).


Telecontrol sought revocation of the Patent on the ground that Arbitron was not entitled to the Patent (under section 138(3)(a)), because the Patent was granted contrary to section 64(2), and that Arbitron was not entitled to obtain something that it had already obtained.

The Court commented that the grounds for patent revocation are directed to serious defects and matters of critical significance, whereas, apart from confusion of the public (e.g., which may arise due to double licensing), double patenting has no significant undesirable consequences. The Court reasoned that double patenting does not create a greater right to exploit an invention than would already exist, and in any case, the concept of entitlement in section 138(3) is concerned with entitlement in relation to the invention, not entitlement in relation to grant. The Court therefore held that Arbitron was entitled to the Patent and the claim for revocation failed.

Rectification of the Register

Telecontrol contended that the Register ought to be rectified by removing the entry of the Patent from the Register, as allowed for under the Act for an entry either made without sufficient cause or wrongly existing (sections 192(1)(b) and (c)). The Court observed that the Register of Patents merely records rights that have already been conferred, and that entry in the Register does not itself confer rights; in a contrasting example, under the Real Property Act, property title depends upon registration. Correctness of the Register is therefore to be determined based on ownership, rather than ownership being determined by particulars recorded in the Register.

The Court held that it is the sealing of a patent that creates the rights of the patentee, and not the entry of consequent details into the Register, and thus, since the Patent had in fact been granted (albeit erroneously), the entry in respect of the Patent in the Register did not itself wrongly exist. Telecontrol was therefore not able to establish a basis for rectification of the Register.
As Telecontrol’s other claims for invalidity, relating to fair basis, novelty and inventive step, also failed, the Patent was held to be valid (although not infringed). In obiter, Justice Emmett commented that a potential right for review of a decision of the Commissioner in relation to double patenting may be available under the Judicial Review Act (1977) or the Judiciary Act (1993), although these remedies were not pursued by Telecontrol. In this regard, the Court was informed by representations from the Commissioner of Patents, who did not appear to object to this possible avenue for relief.


This case clarifies that once the Patent Office has granted a standard patent, or certified an innovation patent, revocation based on a ground of double patenting cannot succeed. Before grant or certification, however, the double-patenting requirements apply even to differing claims of respective patents, where the differences are not “material”.

The Court’s rejections of Telecontrol’s arguments seem to be based on sound reasoning: Telecontrol was reaching beyond the main established grounds in making arguments for both Arbitron’s lack of entitlement, and rectification of the Register, and the Court did not see fit to extend the scope of these grounds. However Justice’s Emmett’s comments on possible alternative avenues for relief based on judicial review of the Patent Office’s original decision remain an issue for patentees with granted patents, and/or certified innovation patents, having similar claims.


1. An innovation patent is a “lesser” form of patent: it can have up to only 5 claims and 8 years’ term. An innovation patent is granted based only on formalities, but cannot be used to assert rights until it is “certified”, which requires examination by the Patent Office. Certification of an innovation patent is thus equivalent to grant of a standard patent.
2. According to the current Australian Patent Office Manual of Practice and Procedure.