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Case Analysis: Tapas Chatterjee Vs Assistant Controller of Patents

Article by Priyanka Rastogi


Section 3(d) of the Indian Patents Act, 1970 has a special place in India’s patent system. It requires more inspection of patent applications pertaining to methods in this area. Patents cannot be issued for the bare use of a known process as per Section 3(d), unless it yields a novel end-product or uses at least one novel reactant. In Tapas Chatterjee v. Assistant Controller of Patents[1], the Hon’ble Delhi High Court (hereinafter referred to as “the Hon’ble Court”) upheld the Controller’s refusal order and conducted a thorough analysis of the claimed subject matter’s inventive step and patentability in accordance with Section 3(d) of the Indian Patents Act in an order dated March 10, 2023.


Appellant Tapas Chatterjee filed an appeal in which she contested the Assistant Controller of Patents’ s decision to deny a patent for a patent application. According to Sections 3(d) and 2(1)(ja) of the Indian Patents Act, the refusal was made for lack of patentability and absence of inventive step, respectively. The current appeal was filed in accordance with Section 117A of the Patents Act of 1970 (hereinafter referred to as “the Act”) and challenges the refusal of Indian Patent Application for the invention made by Respondent No. 1. The subject application was evaluated by the Indian Patent Office, which then issued a First Examination Report (FER) on February 25, 2020, in which the Patent Office raised a number of objections. The main objections were related to the Claims which were falling under Section 3(d) of the Act and lack of inventive steps under Section 2(1)(ja) of the Act.


  • The contested order’s two reasons for rejection were as follows: In accordance with Section 3(d) of the Act, non-patentability and According to Section 2(1)(ja) of the Act, the submitted patent application lacks innovative step.
  • Regarding Section 3(d), Assistant Controller of Patents and Designs (Respondent) contended that neither a new reactant nor a new product was produced throughout the process of the subject application. The Respondent argued that the subject invention did not deviate from the principles of D2 with regard to Section 2(1)(ja). “Merely because the appellant uses the thermal decomposition process to split one compound into two or more new compounds would not result in any technical advancement when compared to the cited prior art references,” they claimed. The final product in all the cited prior art publications D1–D4 is the same, i.e., potassium sulphate, indicating that the claimed technique does not result in the production of a novel product.


  • The Delhi High Court’s ruling in the matter of “Tapas Chatterjee vs. Assistant Controller of Patents and Designs and Anr.[2] provides insight into how Section 3(d) of the Indian Patents Act should be interpreted and applied in respect to well-known processes. The Court’s ruling highlights the necessity of novelty and inventive step in order to grant a patent and reiterates the stringent conditions for patentability.
  • The Court carefully considered Section 3(d)’s requirements in this case and noted that a patent for a known process can only be issued if it yields a new product or includes at least one new reactant. The conditions for patentability are not met by simple combinations of well-known techniques without any extra components resulting in innovation or inventive step. The Court’s ruling emphasizes the significance of the “new product” or “new reactant” criteria in figuring out whether established techniques can be patented. It makes it clear that procedures have a smaller range of patentability than substances do. While the development of a new form of a substance that is already known needs improvement of that substance’s existing efficacy, no similar requirement exists for procedures that are already known.
  • Both of the reasons given by the Controller for rejecting the subject patent application under Section 15 of the Act have been sustained in light of the overall facts and circumstances of this case. According to Section 3(d) of the Act, the subject patent application is not patentable, and Section 2(1)(ja) of the Act’s requirements for innovative step are not met by it.


The Delhi High Court’s ruling establishes a precedent for determining whether known methods are patentable and offers helpful direction on how Section 3(d) should be interpreted. It emphasizes how important it is to satisfy the legal requirements, such as those relating to novelty and inventive step, and it serves as a warning to those involved in the biological sciences to carefully consider their claims before applying for patent protection. This decision encourages innovation and makes sure that patents are only issued for real technological improvements that advance society by respecting the high standards for patentability.

[1] 2023 SCC OnLine Del 1444.

[2] 2023 SCC OnLine Del 1444.