Summary
In the case of Daikin Industries Ltd. v. Assistant Controller of Patents and Designs, the Delhi High Court held that amendments to patent claims can be permitted even at the appellate stage if they satisfy the requirements of Section 59 of the Patents Act, 1970. The court found that Daikin’s proposed amendment did not broaden the scope of the original claims and was supported by the specification. The court therefore allowed the amendment and directed the Indian Patent Office to examine the amended claims afresh.
Background
Daikin filed an Indian patent application relating to a shell and plate heat exchanger filed on June 23, 2022, claiming priority from a Japanese patent application filed in 2020. The Indian Patent Office issued a First Examination Report on November 10, 2022, raising objections of lack of inventive step in light of several prior art documents.
Daikin filed a response to the First Examination Report along with amended claims. Subsequently, in a hearing notice, the Indian Patent Office cited a new prior art document and raised an objection that the invention lacked novelty. After hearing submissions, the Indian Patent Office refused the application on April 10, 2024, on the grounds that the claimed invention lacked novelty in view of the cited prior art.
Aggrieved by this decision of the IPO, Daikin challenged the refusal before the Delhi High Court and sought permission to amend claim 1 through auxiliary requests.
Questions Before the Court
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- Whether amendments to patent claims can be permitted at the appellate stage in an appeal against refusal of a patent application.
- Whether Daikin’s proposed amendment to claim 1 complied with the requirements of Section 59 of the Patents Act, 1970.
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Daikin’s Arguments
Daikin argued that the proposed amended claim incorporated limitations from the original claims and specification. According to Daikin, the amendment did not broaden the scope of the claims and therefore complied with Section 59 of the Patents Act.
Daikin also submitted that the amended claim was identical to the claim granted by the United States Patent and Trademark Office. Daikin pointed out that the same prior art document relied upon by the Indian Patent Office had been considered by the United States Patent and Trademark Office before granting the corresponding patent.
Based on these submissions, Daikin requested the court to permit the amendment and allow the filing of the amended specification before the Indian Patent Office for fresh examination.
Indian Patent Office’s Arguments
The Indian Patent Office submitted that there is no legal prohibition on allowing amendments to claims at the appellate stage. However, the Indian Patent Office stated that such amendments must satisfy the requirements under Section 59 of the Patents Act.
Court’s Analysis
The court stated that amendments to patent claims may be permitted even at the appellate stage if the requirements of Section 59 are satisfied. According to the court, the High Court, while hearing an appeal against the refusal of a patent application, exercises powers similar to those of the Controller under Section 15 of the Patents Act.
The court relied on earlier decisions of the same court, which held that amendments can be permitted during appellate proceedings as long as the amended claims remain within the scope of the originally filed claims.
The court stated that Section 59 allows amendments only by way of disclaimer, correction, or explanation. According to the court, amendments cannot introduce new subject matter that was not disclosed in the original specification.
After examining the proposed amendment, the court observed that the amended claim merely incorporated limitations already disclosed in the specification. In the eyes of the court, the amendment did not broaden the scope of the original claim and therefore satisfied the conditions under Section 59.
According to the court, since the amendment was supported by the specification and fell within the scope of the original claims, it could be permitted at the appellate stage.
Findings
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- The court allowed the proposed amendment to claim 1 as it complied with Section 59 of the Patents Act.
- The court set aside the refusal order issued by the Indian Patent Office.
- The court remanded the matter to the Indian Patent Office for fresh examination after Daikin files the amended specification.
- The court directed the Indian Patent Office to issue a fresh hearing notice and decide the matter expeditiously.
Case citation: Daikin Industries Ltd. v. Assistant Controller of Patents and Designs, C.A. (COMM.IPD-PAT) 56/2024 (Delhi High Court, decided on 26 February 2026). Available on: https://indiankanoon.org/doc/115182081/
Authored by Gaurav Mishra, BananaIP Counsels