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  • Writer's pictureMansi Goel

India: Delhi High Court rules on the scope of permissible claim amendments in patent applications

In a recent judgment passed by the Hon’ble Delhi High Court (hereinafter ‘the Court’) in the matter of Nippon A&L Inc. vs. The Controller of Patents[1], the Court clarified that in case of amendment to a patent specification, the invention before and after amendment need not be identical. A single judge bench comprising of Justice Pratibha M. Singh opined that amendments to a patent specification or claims prior to grant ought to be construed more liberally than narrowly, and the only consideration that must be kept in mind is that the amended claims are not inconsistent with the earlier claims in the original specification. As per Section 59(1) of the Indian Patents Act, 1970 (hereinafter the ‘Act’) amendments to the claims cannot be allowed if the amended claims would not fall wholly within the scope of the claims before the amendment. Brief facts of the case:

The appellant sought patent protection for a “copolymer latex” product and process, and the Patent Office raised an objection that the scope for which the protection was sought was not clear from the wordings of the claims. The Appellant carried out minor amendments to the claims to meet the objections. Thereafter, a hearing notice was issued reiterating the objections and the Appellant amended the “product by process” to “process” claims. The dispute was heard by the Deputy Controller of Patents, who was of the opinion that the process was not claimed earlier and hence the same was beyond the scope of claims and not allowable under Section 59(1) of the Act.

Court’s Observation and Decision:

The Hon’ble Court observed that “It is common understanding in the field of patents that product claims are much broader than process claims. A product claim, if granted, confers a monopoly on the patentee for the product itself, irrespective of the process by which the said product has been made. However, in the case of a process claim, the exclusivity or the monopoly is restricted to the manner or method by which a particular product is manufactured, and if the same product is manufactured or achieved through a different process or method, the exclusivity of the patentee cannot usually extend to such different process or to the product manufactured by the different process. However, when there are ‘product by process’ claims, the extent of monopoly depends upon reading of the claims in each case”.

The Court further noted that Section 59(1) of the Act as it exists presently in the statute came into effect vide Patent (Amendment) Act, 2002, where the phrase "except for the purpose of correcting an obvious mistake" has been substituted with "except for the purpose of incorporation of actual fact". Thus, the Court held that the amendment to Section 59(1) was made to provide broader and wider admissibility for amendments so long as they are disclosed in the application and the scope of the claims is not expanded.

Furthermore, the Court relied upon the judgement of Konica/Sensitizing [1994] EPOR 142[2] in which the Appellate Board categorically held that the conversion and change in category of ‘product by process’ claims to ‘process’ claims was clearly admissible. Reference to Article 123 of the European Patent convention was also made in this respect. The Court also relied upon the Ayyangar Committee Report[3]. The intention of this Report was to give broader and wider permissibility for amendment of claims and specification prior to the grant and restrict the same post the grant and advertisement thereof.

Therefore, the Hon’ble Court opined that “in the present case, the Applicant is amending and narrowing the scope of the claims and not expanding the same. The process sought to be claimed in the amended claims has been clearly disclosed in the patent specification. The said process is not sought to be added newly by way of an amendment. The amendment is, thus, within the scope of the patent specification and claims as originally filed”.

Finally, the appeal was allowed and the Hon’ble Court clarified the scope of amendments that can be carried out under Section 59 of the Act.

For any queries, please feel free to write to the author, Ms. Mansi Goel, at

[1] [2] [3]


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