By Jigyasa Pareek

Patent disputes typically arise from refusals. In Yangtze Memory Technologie Co. Ltd. vs Union of India & Anr. [W.P.(C)-IPD 10/2025], however, the Delhi High Court was faced with an unusual situation, an applicant challenging the grant of its own patent on the ground that the application was allowed without prior notice or the promised opportunity of further hearing, thereby depriving it of the opportunity to file a divisional application under Section 16 of the Patents Act.

The subject patent application number 202127020980, entitled “Novel 3D Nand Memory Device and method of forming the same”, was filed as a national phase application in May 2021. During examination, the Controller raised objections under Section 10(5) of the Patents Act on the ground that the claims contained a plurality of inventions which were not linked by a single inventive concept. The Applicant, however, consistently maintained that the independent claims were unified by a common inventive concept and sought allowance of all claims within a single application.

Instead of filing a divisional application at that stage, the Applicant responded to the First Examination Report by amending the claims and defending the unity of invention. The same position was reiterated at the hearing stage. Written submissions filed after the hearing emphasized that the claims were linked by a single inventive concept and should be allowed together.

In those written submissions, the Applicant indicated that if the Controller were to conclude that the claims represented distinct inventions, one set of claims could be pursued in a divisional application. However, this statement was framed as an alternative course of action contingent upon an adverse finding on unity of invention. The Applicant continued to press for acceptance of the claims in a single application.

The Controller ultimately accepted the Applicant’s submissions, waived the objections and granted the patent on 26 July 2024. The grant order recorded that the amended claims satisfied the statutory requirements and that the objections raised in the hearing notice stood resolved.

The Applicant attempted to file a divisional application a few days later on 31 July 2024. The Patent Office declined to accept the filing on the ground that Section 16 of the Patents Act permits divisional applications only before the grant of the parent patent.

The Applicant then approached the Delhi High Court, presenting the matter as a case where it had been deprived of a statutory right. According to the Petitioner, it had always intended to file a divisional application and had communicated this intention during the hearing. It was argued that the Applicant had instructed its patent agents, before the grant, to prepare a divisional application and had communicated its intention to the Controller during the hearing. According to the Petitioner, the Controller had indicated that further opportunity would be granted and had reserved decision on the allowability of claims. The Applicant therefore proceeded on the understanding that additional time would be available to file the divisional application.

It was further argued that the grant of the patent on 26 July 2024 came contrary to this understanding. Upon discovering the grant, the Applicant claimed to have immediately attempted to file a divisional application along with requests under Rules 137 and 138, but the electronic filing system did not permit such filing after grant. The Applicant relied on a series of post-grant communications and representations made to the Patent Office to demonstrate that it had acted diligently and had never intended to abandon its right to file a divisional application.

On this basis, the Petitioner contended that it had been effectively deprived of a statutory right despite bona fide efforts and that the Controller ought to permit filing of the divisional application.

The Patent Office disputed this account and contended that the Applicant had ample time to file a divisional application but had chosen not to do so. It was argued that no clear intention to file a divisional application had been communicated during prosecution and that the Applicant had in fact sought expeditious allowance of all claims in a single application. According to the Respondents, the attempt to file a divisional application after grant was contrary to the express language of Section 16.

In deciding the matter, the Court undertook a detailed examination of Section 16 and the prosecution history. The Court noted that Section 16 permits filing of a divisional application either voluntarily or to remedy an objection regarding plurality of inventions, but in either case the application must be filed before grant of the parent patent. The Court therefore examined the record to determine whether the unity objection raised by the Controller had in fact led the Applicant to pursue division of the application.

While the Court confirmed that objections regarding plurality of inventions had been consistently raised, it found that the Applicant had consciously elected to defend the unity of invention rather than divide the application. The reference to a divisional application in the written submissions was held to be merely a conditional alternative in case the unity objection was sustained, and not an expression of a definite intention to file a divisional application. Since the Controller accepted the Applicant’s submissions and waived the objection, the contingency for filing a divisional application never arose.

The Court emphasized that Section 16 clearly permits filing of a divisional application only before grant of the parent patent, and that the onus and discretion to exercise this right lies entirely with the applicant. The Applicant had more than three years to file a divisional application but chose not to do so. The attempt to file a divisional application after the patent had been granted was therefore impermissible.

Rejecting the argument that the grant of the patent had occurred without warning, the Court held that the Patents Act imposes no obligation on the Controller to give advance notice before granting a patent. Once the application is found to be in order, Section 43 requires the Controller to proceed with the grant as expeditiously as possible. The Applicant could not claim a right to be alerted that the grant was imminent.

The Court also distinguished the decision of the Madras High Court in BASF SE vs Deputy Controller of Patents, relied upon by the Petitioner. In that case, the divisional application had been filed before the applicant became aware of the grant of the parent patent. In contrast, the present case involved an attempt to file a divisional application after the grant had already taken place.

Having chosen to defend the unity of invention and having succeeded in obtaining grant of the patent, the Applicant could not subsequently seek to divide the application. The writ petition was accordingly dismissed.