Can a patent application be rejected merely because earlier technologies appear broadly similar, without a proper examination of the technical distinctions claimed by the inventor? This question came before the Delhi High Court in The Nippon Signal Co. Ltd. v. Assistant Controller of Patents and Designs1, where the Court examined the standard for determining “inventive step” under the Patents Act, 1970 and the obligation of patent authorities to issue reasoned decisions grounded in technical analysis rather than conclusory findings.
The dispute arose from a patent application filed by Nippon Signal Co. Ltd., a Japanese company engaged in railway signalling technologies, for a “Redundant Control Device and System Switching Method.” The invention related to synchronized active and standby train control systems capable of seamless switchover during operational failures while reducing hardware complexity and switching delays. While the invention involved complex engineering architecture, the broader issue before the Court was whether the Patent Office had adequately considered the applicant’s technical submissions before rejecting the application for lack of inventive step.
Inventive Step, Prior Art, and the Duty to Give Reasoned Decisions
Nippon Signal filed Indian Patent Application No. 201617036284 seeking protection for a low-cost redundant train control device in which active and standby systems operated in synchronization rather than through a conventional master-subordinate structure. According to the applicant, the invention eliminated mirror-memory hardware and relay-based switching circuits, reduced signal transmission delays, and enabled immediate switchover between systems during failures.
Following examination, the Patent Office issued a First Examination Report raising objections relating to lack of novelty, lack of inventive step under Section 2(1)(ja), non-patentability under Section 3(k), insufficiency of disclosure, and lack of clarity. Nippon Signal responded by filing amended claims and detailed technical submissions distinguishing its invention from prior art documents D1 and D2. However, the Assistant Controller rejected the application on 18 July 2024 on the ground that the invention lacked inventive steps in light of D1 and D2, leading to the appeal before the Delhi High Court.
Arguments Advanced by the Parties
Before the Delhi High Court, Nippon Signal argued that the Patent Controller failed to appreciate crucial technical distinctions between the claimed invention and the cited prior art. The company contended that D1 merely disclosed a duplex processor system where the secondary CPU remained inactive until failure of the primary system and operated through a multi-step handshake protocol. In contrast, the claimed invention maintained both systems in continuous synchronized operation, enabling immediate switchover in the next operational cycle without requiring mirror-memory comparison or handshake confirmation.
The appellant further argued that the invention introduced a reversible switchover structure allowing the original active system to regain control upon recovery, unlike the permanent one-way failover mechanism disclosed in D1. It was also submitted that the invention reduced hardware complexity by using simple serial communication lines instead of complex parallel interfaces and relay-based switching circuits.
With respect to D2, Nippon Signal argued that although it related to train control systems, it did not disclose the synchronized controller architecture or the coordinated active-standby relationship claimed in the invention. The appellant maintained that none of the cited prior art references would motivate a person skilled in the art to arrive at the claimed invention.
The Patent Office defended the rejection by arguing that D1 and D2, either individually or collectively, disclosed all essential elements of the claimed invention. According to the Respondent, D1 already taught synchronized fault-tolerant duplex systems involving automatic switchover and shutdown of faulty systems, while adapting such technology to train control systems was merely an obvious field-of-use modification that a person skilled in the art could easily implement. The Respondent further argued that reduced switching time and lower cost were expected outcomes of known redundant control systems rather than indicators of inventive ingenuity.
The Court’s Findings
In examining the dispute, the Delhi High Court referred to Sections 2(1)(j) and 2(1)(ja) of the Patents Act, 1970 governing novelty and inventive step. The Court relied upon Biswanath Prasad Radhey Shyam v. Hindustan Metal Industries2, where the Supreme Court held that an invention would not qualify for patent protection if it appeared obvious to a person possessing ordinary skill in the relevant field.
The Court also relied on F. Hoffmann-La Roche Ltd. v. Cipla Ltd.3, which emphasized that obviousness must be assessed from the perspective of a person skilled in the art without hindsight reconstruction. Further reliance was placed on Agriboard International LLC v. Deputy Controller of Patents and Designs4 and Avery Dennison Corporation v. Controller of Patents and Designs5, where the Delhi High Court recognised the “could-would” approach while assessing inventive steps. The Court reiterated that the relevant inquiry is not whether a skilled person could combine prior art references, but whether prior art would actually motivate such a person to arrive at the claimed invention.
The judgment also referred to Biomoneta Research Pvt. Ltd. v. Controller General of Patents Designs and Another6, where it was held that a synergistic combination producing improved technical results may constitute patentable subject matter even if individual components are known. Importantly, the Court relied upon Boehringer Ingelheim Vetmedica GmbH v. Controller of Patents7, where it had previously held that failure to consider post-hearing written submissions and amended claims constitutes a serious procedural infirmity warranting remand.
Applying these principles, the Delhi High Court found that the impugned order failed to adequately engage with the appellant’s technical submissions and amended claims. The Court observed that the Patent Controller had not meaningfully analysed several asserted distinctions, including continuous synchronization between systems, elimination of handshake latency, reversible switchover capability, absence of mirror-memory architecture, and reduction in hardware complexity.
The Court held that patent adjudication must be based on scientific reasoning and proper evaluation of the applicant’s submissions rather than broad assertions that prior art renders the invention obvious. Accordingly, the Court set aside the rejection order dated 18 July 2024 and remanded the matter to the Patent Office for fresh consideration after taking into account the applicant’s written submissions, amended claims, and settled legal principles governing inventive step. However, the Court clarified that it had expressed no opinion on the ultimate patentability of the invention.
Conclusion
The decision in The Nippon Signal Co. Ltd. v. Assistant Controller of Patents and Designs emphasises that patent refusals cannot rest on generalized findings of similarity without a detailed technical examination of the claimed invention and the prior art. The judgment also strengthens the procedural obligation of patent authorities to meaningfully consider amended claims and post-hearing submissions before arriving at conclusions on inventive steps.
For patent litigators, in-house counsels, and IP practitioners, the ruling underscores the importance of building detailed technical differentiation records during prosecution and appellate proceedings. The Court’s reliance on the “could-would” test further clarifies that obviousness cannot be established merely because prior art components are theoretically capable of combination; there must be demonstrable motivation for a person skilled in the art to arrive at the claimed invention.
Expositor(s): Adv. Aparna Shukla
