Ever Evolving Jurisprudence Of Divisional Patent Applications In India

The jurisprudence of divisional patent applications in India has undergone a marked transformation in recent years, shaped largely by judicial interpretation.

Section 16 of the Patents Act, 1970, is intended to allow an applicant to pursue distinct inventions disclosed in a parent application without losing priority in a divisional application. It reads:

"A person who has made an application for a patent under this Act may, at any time before the grant of the patent, if he so desires, or with a view to remedy the objection raised by the Controller on the ground that the claims of the complete specification relate to more than one invention, file a further application in respect of an invention disclosed in the provisional or complete specification already filed in respect of the first-mentioned application".

A plain reading of the provision makes the following aspects clear:

• The divisional application can be filed at any stage before grant of patent on the parent application; and
• The subject matter being pursued in the divisional application cannot lie beyond the subject matter originally disclosed in the parent application.

Plurality is a 'sine qua non'

For years, innovators interpreted Section 16 as permitting divisional applications to be filed either voluntarily by an applicant or to remedy an objection raised by the Controller regarding plurality of distinct inventions in the parent application. Such an interpretation led to the filing of divisional applications with the same claims as the parent application, particularly in situations where the parent application was at risk of rejection by the Patent Office. Applicants used this strategy to keep the same subject matter under examination. This may be linked to the fact that the Indian Patents Act does not contain a provision analogous to that of a 'continuation application' in the United States, which can be used to continue prosecution of subject matter rejected by an Examiner while separately securing allowance of subject matter deemed patentable.

That said, while dealing with such cases, the erstwhile Intellectual Property Appellate Board (IPAB), clarified on numerous occasions that the presence of distinct inventions was a pre-requisite for a valid divisional application. Its 2011 ruling in LG Electronics Inc v. the Controller of Patents & Designswas significant. It held that the phrase 'if he so desires' did not confer an unconditional right on the applicant; filing of a divisional application was only justified if more than one invention was shown in the parent application. In other words, the term 'or' in Section 16(1) after the expression 'if he so desires' had been used conjunctively by the legislature, not disjunctively. In this context, the IPAB read Section 16 with Section 10(5) (dealing with contents of a patent specification) of the Indian patent statute – the latter stipulates that "claims of a complete specification shall relate to a single invention or to a group of inventions linked so as to form a single inventive concept".

Further, in the matter of Syntonix Pharmaceuticals, Inc v. Controller General of Patents & Designs (2013), the IPAB clarified that once a divisional application is filed in order to remedy an objection regarding plurality of distinct inventions in the parent application, then the Patent Office cannot rescind its stand and question the validity of such divisional applications.

In view of such orders, the Patent Office began following a very narrow approach towards divisional applications often questioning the validity of voluntary divisional applications (irrespective of existence plurality of invention) on the ground of absence of objection regarding plurality of invention in the parent application.

Once again, the IPAB clarified that the Controller's objection regarding plurality of invention is not necessary, but the existence of plurality in the parent application is pre-requisite condition. In the matter of Milliken & Company v Union of India, the voluntarily filed second divisional application, in the absence of an objection in the first divisional application, was held valid.

What if distinct inventions are disclosed but do not form part of claims in the parent application?

This brings us to the interpretation of Section 16(3) of the Act, which has been another point of contention and reads as:

"The Controller may require such amendment of the complete specification filed in pursuance of either the original or the further application as may be necessary to ensure that neither of the said complete specifications includes a claim for any matter claimed in the other".

As a corollary of this provision, the Indian Patent Office questioned divisional applications that were filed voluntarily by applicants to cover the scope of a distinct invention disclosed in the parent application but not covered by the original claims of the parent application. The Delhi High Court supported this stance in Boehringer Ingelheim International GmbH v. The Controller of Patents (2022), wherein the single judge ruled that a divisional application is maintainable only if plurality exists in the claims of the parent application.

This position was viewed as a very narrow interpretation of the law - ignoring aspects related to provisional applications and disclosures in the description - and thus, did not receive much appreciation from stakeholders.

The Division Bench of the Delhi High Court revisited the criteria inSyngenta Limited v. Controller of Patents and Designs (2023) and ruled that "while plurality of inventions may be the criterion for filing a divisional application, the 'plurality' need not be restricted only to the claims. The presence of more than one invention may equally be ascertained from the provisional/ complete specification".

Per the bench, "Section 16 speaks both of a provisional or a complete specification. However, in the case of a provisional filing, claims need not be specified at all. If the view as expressed in Boehringer Ingelheim were to be accepted no divisional application would be maintainable in a case where a provisional specification has been presented".

The court overruled the Boehringer decision and held that there was no justification to restrict the filing of a divisional only to a situation where the plurality of inventions is found in the claims. If a distinct invention is disclosed in the description of a patent application, a valid divisional application could be filed for the said subject matter on the basis of such disclosure alone.

This decision is now supported in Rule 13(2A) introduced through the Patents (Amendments) Rules, 2024. The new Rule states that, "a patent applicant may, if he so desires, file one or more further applications under section 16, including in respect of an invention disclosed in the provisional or complete specification or a further application filed under section 16".

Lingering challenges

Despite the distance travelled, some issues remain unsettled - one of them being whether a patent application can contain multiple independent claims covering the same aspect of an invention. Instead of objecting on the ground of plurality of inventions, Controllers often reject such claims as 'inconsistent', requiring applicants to limit themselves to a single independent claim for each aspect of the invention.

If an applicant chooses to pursue deleted claims through a divisional application, the burden lies on it to prove that there is more than one invention. The applicant must show that not only is there no overlap in the scope of claims but also that the claims of the divisional do not share a single inventive concept with the claims of the parent application.

To remedy matters, allowing multiple independent claims for the same aspect of an invention in a patent application may be considered, as there is no specific prohibition in the Indian Patents Act regarding the same. Alternatively, for the purpose of divisional applications, the term 'more than one invention' may be interpreted to mean an invention, the scope whereof does not conflict with the scope of the invention claimed in the parent application.

Another challenge came to light in BASF SE v. Deputy Controller of Patents and Designs (2024) before the Madras High Court - how the uncertainty of grant timelines of patent applications impacts the filing of divisional applications in India. This was a case involving rejection of a divisional application by the Patent Office as the same was filed on the same day as grant of patent. The court noted that it was impossible for an appellant to know the exact time a patent had been granted. It quashed the Patent Office's order and remanded the matter back for consideration of the divisional application on its merits.

Unlike earlier practice, the Indian Patent Office no longer issues a notice of allowance before granting a patent. Therefore, applicants should ideally file a divisional application as soon as they decide to pursue a particular subject matter in a divisional application. It is also prudent to file the divisional before submitting a response to any outstanding office action, to avoid complications in prosecution.

Despite a few unresolved concerns, the jurisprudence on divisional applications has evolved significantly. Indian courts have repeatedly taken a pro-innovator stance and provided much needed clarity on contentious aspects. Overall, these developments signal a decisive shift toward a more predictable and innovation-driven patent landscape in India.