Space Reduction: Are Restricted Patent Claims Valid Amendments?



Patent law strongly emphasizes the importance of filing an application for protection as early as possible in the inventive process, in order to obtain the necessary rights and advantages. But these apps are by no means set in stone. It is possible to amend patent applications, and in India, amendments can be made both while an application is pending and after a patent has been granted, subject to the appropriate permissions from the Controller.

Section 59 of the Indian Patents Act 1970 (the Act) contains the substantive provisions relating to amendments to a patent application. Section 59(1) deals with amendment of a pending application and Section 59(2) deals with post-grant amendment. Specifically, under Article 59(1), changes are only permitted if the following conditions are met:

  • The change must be in the form of a disclaimer, correction, or explanation.
  • The amendment is intended to incorporate real facts.
  • The effect of the amendment should not be to modify the specification to claim or describe something that was not disclosed in substance or that is not indicated in the originally filed document.
  • Amended claims must come within the scope of the claims as originally filed.

A recent decision of the Delhi High Court in Nippon A&L Inc. v. The Controller of Patents (CA(COMM.IPD-PAT) 11/2022, July 5, 2022) to shed judicial light on the interpretation and applicability of this provision, in particular with regard to the conversion of product claims into process claims, which is discussed in this note.


Nippon A&L Inc. had filed an application as an entry into the Indian national phase of the international application for a product of “copolymer latex” and its method of manufacture. It is important to note that he drafted the claims in a “product by processwhich presented the characteristics of the product and the manufacturing process. For example, one of the affirmations taught “A copolymer latex being obtained by emulsion polymerization…”.

The Indian Patent Office (IPO) raised an objection on the grounds of non-inventive step under Section 2(1)(ja) of the Act, non-patentability under Sections 3(d) and 3(e), and stated that the teachings of the claim could not clearly support the scope for which protection was sought. In response, the Applicant submitted an amended set of claims, which were previously defined in ‘product by process‘ format as ‘process only‘ complaints (“An emulsion polymerization process for obtaining a copolymer latex…. “), by providing a clearer and more specific set of demands. However, the Assistant Comptroller of Patents rejected the patent application for two reasons:

  • The new set of amended claims was outside the scope of the original claims; and that the amendment of ‘product claims‘ at ‘handle complaints‘ was not supported by the description in the patent and was therefore rejected under Section 59.
  • The amended claims lacked inventive step.

The applicant preferred to appeal to the Delhi High Court, which was the subject of the present case. The question put to the court was the following: could the claims as originally filed have been changed to method claims by the Appellant? “.

Arguments of the Parties

The claims, originally worded as ‘product by process‘ claims, have been changed to “method/process onlysays, in response to objections raised by the IPO. According to Nippon, such an amendment did not go beyond the scope of the original claims because the original claims included both product claims and process claims. In fact, she argued that by limiting the claims to process, she waived a significant portion of the claims, which cannot be considered covered by section 59 of the Act.

In support, she relied on Article 123 of the 1973 European Patent Convention (EPC) and on the decision of the European Board of Appeal in the Konica/Sensitizing case. [1994] EPOR 142 which stated that “whenever process product claims are amended and the applicant limits the claims to the process only, such amendment may be permitted under Article 123 EPC.”

Two Indian decisions were also invoked: the IPO decision in Antacor SA & Schweiger, Martin (July 18, 2017), where the amendment of ‘product by process’ claims to ‘process only’ complaints, under identical circumstances, was found to be admissible to improve the clarity and finality of the claims; and the decision in The Polymer Corporation patent [1972] CPR 39to argue that “explanatory amendments, which turn ambiguous claims into clearer claims, should be permitted.”

For its part, the IPO argued that “product by processClaims are primarily product claims that are validated for novelty and inventive step in relation to the product rather than the process. Further, he stated that if a claim relates to a process, the scope of the claim is defined by the steps and parameters of the process. He also said that the core of ‘product by process‘ claims is the product and converting the claims related to the product to ‘treat‘ alters the essence of the claims, which is prohibited by law. He also argued that swapping a ‘product patent‘ in ‘treat patent‘ which has not previously been claimed, is not permitted because it expands the scope of the claims.


The court noted that, consistent with the objections raised by the Controller during the prosecution of the patent application at the IPO, the Controller had specifically asked whether the protection sought covered a method or product in its entirety. According to the court, this shows that the original application illustrated a process/method in its claims and, more importantly, that by amending the claims, Nippon itself waived the product part of the claims.

The Court also observed that the process claimed in the amendment was already mentioned in detail in the original full specification. For interpretive guidance here he referred to the Ayyangar committee report, whose stated intention was to give broader eligibility for modifications before grant, and to restrict the same after grant and publicity. The court also noted that the invention before and after modification need not be identical in the case of modification before acceptance, “as long as the invention is comprised in the subject matter disclosed”. In light of this, the court decided that the amendment in this case fell within the scope of the patent specification and claims as originally filed.

By limiting the claims to only “process”, the court said the plaintiff had narrowed the scope of the claims and agreed with the Konika case to consider the conversion of “product-by-process” claims to “process” claims was admissible. . In this context, the court stated that product claims are much broader than process claims; product claims grant patentees exclusivity for the product itself, regardless of the method of manufacture, while process claims limit monopoly rights to the method of manufacture alone, and the patentee’s rights do not extend not extend to different processes or even to the product produced by the different process.

This decision is based on existing case law in several cases, for example, AGC Flats Glass Europe SA v. Anand Mahajan2009 (41) PTC 207 (LED) and Sulfur Mills Limited v. Dharamraj Crop Guard Limited (2021) 87 PTC 567, which ruled that if an applicant seeks to clarify or reduce/condense the claims, possibly restricting the scope of the invention, the amendment should be allowed. The only fact to be considered is that the amended claims must not conflict with the claims filed in the original description.


With this decision, India’s position on amendments is strengthened, in that an amendment in a patent application can only extend to the scope defined by the original claims, and no new matter can be introduced. . The Delhi High Court has also stated that under conditions where one aspect of a claim or set of claims is sacrificed while another is retained, the corresponding modification may be permitted. In this case, where changes to the claims from “product by process” to “process” unambiguously narrowed the scope of the claims, the court noted that the claimed process had already been set forth in the application and therefore , the modifications were covered by the patent specification and claims as originally filed. However, even though the court found that the amended claims met the requirements of Section 59(1) of the Act, for the objections relating to lack of inventive step and non-patentability under sections 3(d) and 3(e) of the Act, the court held that the IPO would have the final say and sent the matter back to the IPO for reconsideration.


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