By Jigyasa Pareek

The Delhi High Court in Dong Yang PC Inc. vs Controller of Patents & Designs [C.A. (COMM.IPD-PAT) 60/2024; decision dated July 1, 2025] underscored the significance of adhering to the principles of natural justice when adjudicating patent applications.

The Appellant challenged the refusal of patent application number 2554/DEL/2013, entitled “Vertical Rotary Parking System”. The application was opposed at the pre-grant stage with objection on the grounds, inter alia, of lack of inventive step. The statement of opposition cited four prior art documents (D1-D4) and shortly before the hearing, the Opponent drew the Controller’s attention to a fifth prior art document (D5). Notably, D5 was a prior patent document belonging to the Appellant itself, which also disclosed a vertical rotary parking system for vehicle storage similar to the invention claimed in the subject application.

In response to the subsequent citation of D5, the Appellant voluntarily amended the complete specification after the hearing was concluded to incorporate the summary of D5 as a prior art and detail the manner in which the claimed invention improved upon D5’s limitations. The Appellant explained that the invention disclosed in D5 had certain issues that resulted in generation of excessive noise during operation. To overcome these issues, the Appellant developed the claimed invention, which was designed to offer a more efficient, safer and quieter vertical rotary parking system.

The Controller rejected the grounds raised in the pre-grant opposition, however, refused the application under Section 15 on the ground of lack of inventive step in view of D5. The Controller also rejected the proposed amendment to the specification. The Controller was of the view that the claimed invention was a mere workshop modification of the invention disclosed in D5 and did not demonstrate any technical advancement over the said prior art. It was held that the only difference between D5 and the claimed invention was the interchange of the male and female portions in the gear mechanism, which, according to the Controller, did not lead to any technical advancement over D5.

During the proceedings, the Controller tried to justify:

• The refusal of the application, arguing that the invention was obvious to a person skilled in the art (PSITA) in view of D5 and lacked technical advancement. It was also argued that the Appellant had failed to substantiate their assertion of technical advantage with adequate technical data.
• The rejection of the amendment, reasoning that the claimed technical advancement over D5 had not been disclosed in the original specification and was raised for the first time in the amendment itself. According to the Controller, the statutory scheme mandates that all material facts, including any claimed technical advancement, must be disclosed in the specification as originally filed.

The Appellant contended that the Controller’s conclusion that the claimed invention was a mere workshop modification lacked a detailed technical analysis and evidentiary support. They also emphasised that the Controller did not assign any reason explaining how the claimed invention would be obvious to a PSITA and relied solely on the observation that the invention involved slight modifications to D5. To support the claims of technical advancement, the Appellant also submitted before the Court a technical evidence affidavit.

The Court concurred with the Appellant’s arguments that the impugned order was unreasoned and held it to be untenable. The Court reaffirmed the principle that simplicity is no bar to patentability.

Referencing the decision in Avery Dennison Corporation vs Controller of Patents [2022 SCC OnLine Del 3659], the Court remarked that if the subject invention was obvious, as the Controller had concluded, then it would have been expected that a PSITA would have made similar modifications to D5 at some point. However, the Court stressed, that no such modifications or improvements had been made in the decade since D5 was published in 2003. The subject application was filed only in 2013. The Court treated the fact that no one else had arrived at the claimed invention in all that time as a significant indicator that the invention was not obvious.

The Court further held that the Controller erred in holding the invention obvious based on common general knowledge without providing any specific reference for the common general knowledge and explaining why a PSITA would apply the knowledge to arrive at the claimed invention. Importantly, the Court also recognised and considered the technical evidence affidavit submitted by the Appellant as a post-filing evidence. This is a noteworthy aspect of the decision, as post-filing evidence is not routinely considered at the appellate stage.

This is an important take-away from the decision that post-filling evidence at the appellant stage can be recognized.

Regarding the amendment of the specification, the Court noted that although D5 should have been disclosed in the background at the time of filing since the Appellant later relied on it to demonstrate technical advancement, if the Controller raises an objection based on a prior art, whether or not it was disclosed by the applicant, the applicant has the right to address that objection by amending the specification. The Controller cannot refuse to consider such an amendment on merits merely because the prior art was not disclosed earlier. Moreover, the Court clarified that as per Section 59 there exists no specific bar for amendment to the specifications even at a subsequent stage.

The Court further highlighted that since D5 was not cited in the First Examination Report and was introduced only before the hearing, the Appellant’s attempt to amend the specification to clarify the technical advancement over D5 was reasonable. The refusal to consider the amendment under Section 59 denied the Appellant a fair chance to respond to the objection, thereby violating the principles of natural justice. The Court also opined that the proposed amendment seemed to comply with the requirements of Section 59.

In view of the foregoing, the Court remanded the matter to the Patent Office for fresh consideration.