Unity of Invention

Double patenting (Rule 46(1)(f)5)

6.94 As set out in Section 80(1)(g), the Registrar may, on the application of any person, by order revoke a patent for an invention on the ground that the patent is one of 2 or more patents for the same invention having the same priority date and filed by the same party or his successor in title. This ground is often referred to as double patenting.

6.95 The Examiner is empowered to determine the matter of double patenting (amongst other matters) when conducting an examination or supplementary examination, under Section 2(1) (see definition of “examination” and “supplementary examination”), Rule 2A(1)(d) and Rule 2A(3)(e).

6.96 According to Section 2(1), “examination” means an examination conducted by an Examiner in relation to an application for a patent to determine such matters as may be prescribed, and “supplementary examination” means a supplementary examination conducted by an Examiner in relation to an application for a patent to determine sub matters as may be prescribed.

6.97 Rule 2A(1)(d) and Rule 2A(3)(e) respectively set out that for the purposes of the definition of “examination” or “supplementary examination” in Section  (1), the matters to be determined by an Examiner when conducting an examination or supplementary examination in relation to an application for a patent includes:

Whether there is –

(i) any other application for a patent for the same invention, with the same priority date, filed by the same applicant or his successor in title; and
(ii) any earlier grant of a patent for the same invention, with the same priority date, to the same applicant or his successor in title.

6.98 An Examiner, in determining a positive finding of double patenting, shall notify the Registrar accordingly in his written opinion (Rule 46(1)(f) or Rule 46(1A (e)). A positive finding of double patenting is considered by the Registrar to be an objection.

6.99 If such a positive finding (i.e. an objection) under Patents Rule 4 (1)(f) or Rule 46(1A)(e) is left unresolved, it shall be contained in the examination report or the supplementary examination report issued by the Examiner. Consequently, the Registrar shall not issue a notice of eligibility under Section 29A(1). It follows that Section 30(b) would not be satisfied, and hence the patent application would not proceed to grant6.

6.100 It follows from Rule 2A(1)(d) or Rule 2A(3)(e) that double patenting only applies to the situation where the same applicant (or their successor in title) makes the two applications. If the applications are made by two different applicants, then the applications are allowed to proceed.

6.101 It should be noted that double patenting is different from Section 1(3) where a Singapore application which is not published at the time of filing of the application in suit may constitute part of the state of the art for novelty purposes. In the case of Section 14(3), the two applications do not share the same priority date and accordingly one is prior art against the other.

6.102 The law applies to both pending applications, as well as granted patents for the same invention. When dealing with co-pending patent applications for the same invention, Examiners should flag any potential double patenting issues to the applicant while continuing with the examination of both applications. It will be up to the applicant how they wish to proceed with the applications in order to avoid double patenting.

6.103 Double patenting will apply if two claims are identical in scope. In most cases, this will occur if the claims are coterminous. This can apply to independent claims where the wording is identical or to dependent claims where the combination of limitations or additional features results in claims having identical scope. Accordingly, Examiners will need to consider both independent and dependent claims in order to determine whether there is a double patenting situation. Double patenting will also apply if the claims use different terminology but are otherwise identical in substance. This will include situations where different terminology is used to define the same invention.

6.104 Double patenting may apply as well in situations where two claims differ in as much as one contains a specific feature while the other defines a more generic group for the corresponding feature. For example, claim 1 in application “A” and claim 1 of application “B” define identical features, except that claim 1 in application “A” further defines a specific feature and claim 1 in application “B” further defines a more generic group of corresponding feature. An objection of double patenting may arise between applications “A” and “B” in such situations if the specific feature is the only one disclosed in the specification of application “B” and there is no basis for reading the specification as constituting a more generic group. However, if application “B” discloses that there is more than one means of performing a particular step or the specific feature may be selected from a group, then no objection should be taken.

6.105 In the case of claims that do not have unity (i.e. they do not share a single inventive concept), they would not be the same invention and double patenting will not occur. Therefore, there should not be double patenting between parent and divisionals if they relate to claims that were objected to for lack of unity in the first place.

6.106 Double patenting has yet to be considered by the Singapore Courts but given the similarity in the law some guidance may be taken from UK precedent.

6.107 In Arrow Electric Switches Ltd’s Applications [1944] 61 RPC 1, the Patents Appeal Tribunal considered a parent application claiming an electric switch A. The specification also contained a claim to the switch when operated with an overload device B – in essence a claim to A + B. The divisional application claimed overload device (B). The UK Intellectual Property Office considered that double patenting existed because the patent to B per se would encompass its use with device A – thus including A + B (that is, a claim to the item per se is a claim to the item in all environments), even if not explicitly defined. They sought that the applicants include a disclaimer in the divisional application to avoid overlap.

6.108 On appeal, Morton J questioned the logic of this approach. Taken to its full extent, the claim to A per se in one would always include within its scope the combination of A + B, and a claim to B per se in the other would always include within its scope the combination of A + B. As a consequence, the divided patent to B per se would always need a disclaimer, regardless of whether or not the parent application contained a claim to the combination of A + B. If for any reason the parent patent to A per se was subsequently made void, the patentee would then have no protection at all over the use of A + B in combination because they had disclaimed it.

6.109 The subsequent UK Patents Act 1977 codified the exclusion to double patenting, as did the Singapore Act. Moreover, the UK Act forbids double patenting for UK national applications and those originating under the EPC and designating the UK. Several decisions have considered the term “same invention” in relation to these provisions which can provide guidance as to the application of the double patent provision in Singapore.

6.110 In Marley Roof Tile Co. Ltd.’s Patent [1994] RPC 231, the Court of Appeal found that a claim to a product will conflict with a claim to the same product as produced by a specific process. This is consistent with the approach that a product by process claim is indistinguishable from a claim directed to the product per se (and made by a different process).

6.111 Several other relevant hearings decisions have issued from the UK Intellectual Property Office. In general, the approach is taken that an objection of double patenting will arise where the claims explicitly include all of the same features (that is they are coterminous, including where the claims are dependent as well as independent), but also where the claims differ in wording but not in substance.

6.112 Kimberley-Clark Worldwide Inc. BL O/279/04 involved a situation wherein (in short) a European patent covered A + B, while the UK patent covered only A. In accordance with the UK examination guidelines, the hearing officer noted that some overlap of claims was allowable. In this case, he considered it useful to consider whether the integer B was an invention in its own right – since the conclusion could then be readily reached that the two patents were for different inventions. Furthermore, he noted that the European patent had been amended to remove claims to A in isolation as a result of opposition proceedings and had been allowed to proceed with claims to the combination. He considered this highly persuasive since the patent would not have been allowed to proceed had it still been to the same invention.

6.113 In SeeReal Technologies SA BL O/261/12, the hearing officer noted that the fact that a claimed invention in a second patent could have been included as a dependent claim in the first patent does not automatically mean there is double patenting. An absence of plurality does not necessarily mean the presence of conflict. Applying this to the case in hand, the hearing officer considered there was a feature that made a substantial difference between some of the objectionable claims and therefore they constituted different inventions. A second difference between the claims was considered implicit since this was the only way described to carry out the particular feature.

6.114 The permissible degree of overlap was also considered in Optinose AS BL O/026/12, wherein the hearing officer stated:

“But even if the divisional application has a claim that falls clearly within the scope of a claim in the parent then it is not necessarily fatal to the divisional application. This is clear from Arrow Electric Switches Ltd’s Applications and Kimberley-Clark Worldwide Inc’s Patent. However, if the two claims are coterminous or the like, in Maag, if in substance they relate to the same invention then there would be conflict.”

In this case, the hearing officer considered the claim of the parent patent included method A, method B and various combinations of the two (these being the various methods disclosed in the specification, but were not specifically defined in the claims). The divisional was limited specifically to method B. The hearing officer therefore concluded that there was no double patenting because the claims were not  coterminous, nor did they in substance relate to the same invention. However, this may be considered on a case by case basis. For example, if a claim clearly defined a method using A or B and the divisional application claims were identical but limited only to the method using B, an objection may be appropriate since the scope of the divisional is identical to one of the alternatives in the first granted patent.

5 In the Patents Act with effect immediately before 14/02/2014, Section 30(3 (e) sets out that it is one of the conditions for grant of a patent that a patent application has no double patenting issue.
6 In contrast, under the Patents Act with effect immediately before 14/02/2014, when there is double patenting, the Examiner does not raise an objection but should include a note indicating the potential double patenting issue in the written opinion. If the written opinion is otherwise clear, an examination report will issue with the note and the Registrar is also advised of the potential double patenting issue. In other words, under the Patents Act with effect immediately before 14/02/2014, the note is not taken to be an unresolved objection but rather an observation. The law did not require the examiner to examine double patenting under Sections 29(5) and (6), though it is a condition for the application to be granted to have no double patenting issue as per Section 30(3)(e).