“Unity of invention” is an essential facet of a patent application in India [1]. The term denotes a situation where the claims of a complete specification relate to either a “single invention” or can be “a group of inventions linked to form a single inventive concept”. If a patent application claims more than one invention, it may be rejected because it lacks unity of invention. Where an application covers more than one inventive concept, this hurdle can be overcome by filing a divisional patent application.[2] Divisional patent applications are applications which have been divided from the main application, also known as the parent application. A divisional application allows an applicant to divide the inventions from the parent application into a separate application for each inventive concept without losing his priority rights.
Assessing unity of invention under Indian Patent LawPlurality of inventions in the parent application is a must for a divisional application, whether it is filed by the applicant or to remedy the Controller’s objection.[3] One of the main objections to a divisional application is that the parent application does not disclose a plurality of invention or that the claims in the divisional application are already claimed, or fall within the scope of claims, in the parent application, or that the claims in the divisional application were not present in the claims of the parent application. In Esco Corporation v. The Controller of Patents & Designs, OA/66/2020/PT/DEL, the IPAB referred to Rule 13 of the Patent Cooperation Treaty, which provides that the requirement of unity of invention for a group of inventions claimed in an international application is fulfilled when there is a technical relationship among those inventions involving one or more special technical feature. The term “special technical features” is defined in the PCT rules as technical features that define a contribution that each of the claimed inventions makes over the prior art.While the IPAB did not issue definitive guidance for assessing unity of invention in an application, their reliance on Rule 13 of the PCT indicated that there should be a technical relationship among the inventions claimed. However, the IPAB also highlighted that care should be exercised during examinations as the mere presence of different embodiments in the specification, which are claimed as an independent set of claims, does not necessarily mean that the application lacks ‘unity of invention’.When can a divisional patent application be filed?The applicant of the parent application can file a divisional application at any time before the grant of the parent patent, either voluntarily or in response to an objection by the patent examiner. Since there is a possibility that a patent for the parent application can be granted at any time after filing a response to the First examination report (FER), it is advisable to file the divisional application at the same time as filing the response to the FER, or as soon as possible thereafter.Fees and examinationA divisional application is a separate application in itself, and therefore separate fees must be paid when filing the application, and a separate request for examination must be made.Under s 16(3) of the Patents Act 1970, the request for examination for a divisional patent application should be filed with the patent office within 48 months from the date of filing of the application or the date of priority of the first mentioned application or within six months from the date of filing of a divisional application, whichever is later.However, it is essential to note that the request for examination of a divisional application should be filed only after filing the request for examination of the parent application.What can be claimed in a divisional application?A divisional application should include a complete specification and should not contain any matter not in substance disclosed in the parent application.[4] The completed specification should make a specific reference to the number of the parent application.The divisional application must not claim any matter already claimed in the parent application or any other divisional application.[5] If there is any overlap of the claims in the parent application with the divisional application, the Controller may seek amendments in the complete specification of the divisional application to ensure that there is no overlapping of claims between these applications to avoid double patenting.How is a divisional application examined?Examination of a divisional application is always done in relation to the parent application. If two or more divisional applications are filed based on a parent application, examination of the second or subsequent divisional application(s) shall be done with reference to the parent application and other divisional application(s) to avoid double patenting.Currently, in order to determine whether the claims of a divisional application have their origins in the parent application, Controllers resort to comparing terms between the application, which is ineffective. While recent cases have provided helpful guidance, there is a need for development in this area, and it will be interesting to note how things will progress in upcoming cases.What is the term of a divisional application?A divisional application is backdated and is deemed to be filed on the date the parent application was filed. The term of each divisional application is 20 years from the date of filing of the parent application.It is important to note that the backdating of an application does not allow the evergreening of patents, even though it allows the filing of multiple applications arising from the parent application. This is because the term of protection is the same as that granted to the parent, and the divisional applications lapse with the parent application. In effect, divisional applications can have a shorter term of protection.Can a divisional application be divided into further divisional applications?Each divisional application is treated as a separate and substantive application in itself. It has been held that filing further divisional applications from a divisional application is permissible, provided that the claims of the further divisional applications have their roots in the claims of the divisional application.[6]In Boehringer Ingelheim International GmbH Vs. The Controller of Patents the Court has made it clear that a divisional application is maintainable only if the claims in the divisional application were present in the claims of the first (parent) application. The decision states that “if the invention [to be pursued in the divisional application] is not contained in the claims of the parent application, the divisional application cannot be permitted to be filed solely on the basis of disclosure made in the specification. If applicants are permitted to file such divisional applications on the basis of disclosure in the complete specification, without such inventions being claimed in parent applications, it would defeat the fundamental rule of patent law i.e., ‘what is not claim is disclaimed’.” [7]Given the current interpretation of the sections governing divisional applications, it is advisable that the parent application is drafted to include claims covering all aspects of the invention and all embodiments of the invention so that the claims of a divisional application, if required to be filed, would have sufficient support in the parent application.[1] S 10(5), The Patents Act, 1970[2] S 16(1), The Patents Act, 1970[3] LG Electronics, Inc A Korean Corporation v/s The Controller Of Patents & Designs Patent Office & Others OA/6/2010/PT/KOL[4] S 16(2), The Patents Act, 1970[5] S 16(3), The Patents Act, 1970 ; LG Electronics, Inc A Korean Corporation v/s The Controller Of Patents & Designs Patent Office & Others OA/6/2010/PT/KOL[6] Esco Corporation v. The Controller of Patents & Designs, OA/66/2020/PT/DEL[7] Boehringer Ingelheim International Gmbh V. The Controller Of Patents & Anr. dated 12th July 2022 C.A. (COMM.IPD-PAT) 295/2022 & I.As.10369-70/2022 https://indiankanoon.org/doc/164938320/ at paragraph 31.
