In a recent ruling of B.V. Draka Comteq v/s The Controller Of Patents, Designs & Trademarks, the Delhi High Court addressed a patent appeal filed under Section 117A of the Patents Act, 1970. The appeal challenged the rejection of a patent application for a "Multimode Fiber" invention, a key innovation in the field of optical fiber transmission. The appellant, dissatisfied with the refusal by the Assistant Controller of Patents and Designs, claimed that the subject invention was novel and had an inventive step, contrary to the conclusions drawn by the respondent.

The subject patent application was filed on April 22, 2010, under the national phase entry of a PCT (Patent Cooperation Treaty) application. The invention was related to multimode optical fiber, particularly used in short-distance transmission systems requiring large bandwidth. The application aimed to improve the design of optical fibers through an innovative "depressed cladding" technique, which allowed better control over the refractive index and increased transmission bandwidth.

However, the Assistant Controller of Patents and Designs (respondent no. 2) issued an order on November 19, 2019, rejecting the application. The primary reasons for refusal were the lack of novelty and inventive step, citing prior art document D3 as evidence of the similarities between the invention and existing technology. The appellant, aggrieved by this decision, filed an appeal before the Intellectual Property Appellate Board (IPAB). Following the dissolution of IPAB in 2021, the appeal was transferred to the Delhi High Court.

The appellant's main contention was that the cited prior art, D3, did not disclose all the essential features of the subject invention, particularly the feature of "depressed cladding" with a refractive index lower than the outer cladding. Additionally, the appellant argued that the co-doping of two dopants in the depressed cladding, a feature central to their invention, was not found in the prior art.

The respondent, in defense, maintained that the prior art D3 adequately disclosed the relevant features, even though the term "depressed cladding" was not explicitly used. The respondent further argued that the appellant's claims were substantially similar to D3, which justified the refusal based on lack of novelty and inventive step.

To assess novelty, the court closely examined the features disclosed in the prior art D3 and compared them with the claims in the subject application. D3 described a graded-index multimode fiber, but crucially, it did not disclose a "depressed cladding" with a refractive index lower than the outer cladding, which is a central feature of the appellant's invention.

The court noted that the appellant’s invention provided a new method of achieving a continuous variation in the refractive index through co-doping with two dopants in both the core and the depressed cladding. This innovative doping technique led to a significant improvement in the control of the refractive index, thereby enhancing the bandwidth of the optical fiber.

The comparison with D3 demonstrated that the latter did not disclose the full range of features in the appellant’s claim, particularly the use of two dopants in the depressed cladding and the resulting control over the refractive index. As such, the court found that D3 did not anticipate the subject invention, and the impugned order’s refusal on grounds of novelty was not well-founded.

The second ground for refusal was the lack of an inventive step under Section 2(1)(j) of the Patents Act. The impugned order, however, failed to provide a detailed analysis or reasoning for this conclusion. The court referred to the principle established in previous judgments, emphasizing that to reject a patent application on the grounds of lack of inventive step, the Controller must conduct a thorough analysis, considering the existing knowledge, the invention disclosed in the application, and how the invention would be obvious to a person skilled in the art.

In this case, the impugned order did not adequately address these three elements. The court observed that the subject invention was not merely an obvious modification of prior art but involved technical advances that were not evident from the cited prior art. Consequently, the court concluded that the refusal on the grounds of inventive step was also flawed.

After reviewing the arguments, the Delhi High Court set aside the impugned order of refusal and remanded the case back to the Patent Office for a fresh hearing. The Court directed the Patent Office to pass a reasoned order considering all the relevant factors, including a detailed analysis of the inventive step, within three months. The appellant was also granted the opportunity for a fresh hearing.

The Court emphasized the importance of a reasoned decision in patent matters, especially in cases involving complex technologies like optical fibers. The judgment highlighted that a patent application cannot be rejected merely based on generic conclusions, without a detailed analysis of the invention’s uniqueness and technical advancements over prior art.

This judgment underscores the importance of thorough and reasoned decisions by patent authorities in determining the patentability of inventions. The case also serves as a reminder that in patent litigation, the distinction between prior art and the claimed invention must be carefully examined, especially when the technology in question involves innovative solutions. The appellant's invention for multimode fiber, with its novel "depressed cladding" feature and co-doping technique, has now been given a chance for a fair reassessment. The outcome of this appeal could significantly impact the future of optical fiber technology, particularly in high-bandwidth, short-distance transmission systems.