The Delhi High Court’s decision in The Nippon Signal Co., Ltd. vs Assistant Controller of Patents and Designs [C.A.(COMM.IPD-PAT) 84/2024] is an important addition to Indian patent jurisprudence on inventive step and the quality of reasoning required in Controller’s orders.

The Court set aside the refusal of patent application number 201617036284, entitled “Redundant Control Device and System Switching Method”, holding that the Controller must engage with the applicant’s technical case, apply the correct legal tests, and issue a speaking order.

The invention pertains to a redundant control device comprising an active system and a standby system, and a corresponding method for switching between these systems. The primary technical objective is to provide a low-cost redundant control device that does not distinguish a main system from a subordinate system, thereby shortening the system switchover period.

The Controller identified D1 (a Japanese patent disclosing a duplexed CPU operation processor control system) as the closest prior art, finding that it disclosed synchronized active/standby systems, error detection, and switchover. The Controller held that the feature of stopping the active system upon persistent error detection was implicitly disclosed by D1 (read with D2). Further, it the impugned order stated that obviousness test from F. Hoffmann-La Roche Ltd. v. Cipla Ltd. was applied to conclude the claimed subject matter would have been obvious to a normal technical engineer in view of cited prior art documents and common general knowledge.  The Dependent claims were found to be obvious mutatis mutandis on the same reasoning.

The Appellant challenged the refusal on several grounds, contending that:

• The impugned order was non-speaking. The Controller failed to consider the detailed submissions made in response to the First Examination Report (FER) and the post-hearing written submissions, and did not address the technical distinctions drawn between the claimed invention and D1/D2.
• The cited prior art was technically distinguishable from the claimed invention. D1 merely disclosed a generic duplexed CPU operation processor and did not relate to train control, while D2 disclosed a conventional main-slave train control architecture. In contrast, the claimed invention employed synchronized active and standby systems positioned in separate train cars, incorporated a reversible switchover mechanism, and used a dedicated synchronization line to enable immediate switchover without handshake protocols, mirror-memory comparison, or relay-based switching. These features, according to the Appellant, resulted in reduced hardware requirements, lower costs, shorter switchover time, and improved train control.
• Inventive step must be assessed holistically. The Controller impermissibly dissected individual claim elements instead of evaluating the invention as a whole. In this regard, reliance was placed on Avery Dennison Corporation vs Controller, and Groz-Beckert KG vs Union of India.

The Court concurred with the Appellant and found the impugned order to be “completely coloured by the perception of the Respondent that D1 and D2 make the claimed invention obvious” without any reasoned engagement with the Appellant’s submissions.

The Court clarified that:

• Duty to give reasoned orders: The Controller of Patents, while exercising its expert prerogative to determine inventive step, is under a legal obligation to consider all relevant points raised by an applicant, analyse them on merit, and pass a reasoned order grounded in material facts and scientific reasoning.
• Non-consideration of written submissions is a remand ground: The failure to consider and engage with post-hearing written submissions and amended claims submitted during prosecution is itself sufficient cause for setting aside a refusal order and remanding it for fresh consideration.
• The “could-would” test governs inventive step: The correct inquiry is not whether a skilled person could have arrived at the claimed invention, but whether there is a teaching in the prior art that would have motivated such a person to modify the closest prior art to arrive at the subject matter of the claims. 
• Holistic and non-hindsight assessment: Inventive step must be assessed holistically, without the benefit of hindsight, and not by isolating and dissecting individual known components of a combination invention.
• Domain-specificity and train-context advantages matter: The specific architectural and functional advantages arising from the application of a technology to a particular field (train control), including cost reduction and precision control, are relevant and must be assessed in the inventive step analysis.

Finding that the Controller had not analysed the applicant’s distinguishing technical features or applied the correct legal framework for assessing inventive step, the Court quashed the refusal order and remanded the matter for fresh consideration in light of the applicant’s FER response, post-hearing submissions, and the jurisprudence governing Section 2(1)(ja).