Adv. Nishmma James

Non-literal infringement has gained significance with the advancements in technology. When a patent is literally assessed through its claims, it paves an easy way for the infringer to escape patent infringement through verbalism. The judiciary has, from time to time, brought in methods to safeguard the rights of the Patentee. One notable example is the Doctrine of Equivalents, which gained attention in the recent case of SNPC Machines Private Limited & Ors. v. Mr. Vishal Choudary[1]. “Doctrine of equivalents is an equitable doctrine that may apply in a situation where, despite the absence of literal infringement, there still may be an infringement if the product or service in question has a structure or performs a function that is an equivalent of an element recited in the claim”[2]. In the Indian context, Doctrine of Equivalents has served as an important tool to prevent unauthorized reproduction of patented products and preserve the value of patents. Its application and interpretation have been significantly influenced by court rulings.

Tracing the Indian Jurisprudence that shaped the Doctrine of Equivalents

While, the Indian Judiciary has not explicitly used the term “Doctrine of Equivalence” until recently, it has long recognized the concept of non-literal infringement. Early in 1977, in the case of Raj Parkash v. Mangat Ram Chowdhry[3], the Delhi High Court emphasized that the “pith and marrow” of the invention should be looked into rather than getting entangled in detailed specifications or claims. The court also expanded the scope of the patent claims beyond its literal assessment. The Court cited the Australian decision in Beecham Group Limited v. Bristol Laboratories Private Limited[4], which established that infringement can occur even if the essence of the patented article is reproduced without a literal copy.

The Supreme Court of India, in Bishwanath Prasad Radhe Shyam v. Hindustan Metal Industries[5], articulated the principle that patent claim construction requires consideration of the invention’s specifications. The patent claims should not be read in isolation but rather in light of the detailed description provided. When the meaning of the claims is ambiguous, the description becomes a key resource for clarifying the terms within the context provided by the specification. This principle has become essential in evaluating non-literal infringement under the Doctrine of Equivalents.

The first explicit judicial consideration of the Doctrine of Equivalents in India came in the 2008 case of Ravi Kamal Bali v. Kala Tech and Others[6]. The Delhi High Court, in its factual analysis, found that the accused product and the patented product shared the same “usage/purpose,” “type of material,” and “principle.” The court determined that the modification in the primary structure of the product alone did not establish the presence of a distinct invention, as there was no appreciable difference in the constructional and functional aspects. While this case discussed the Doctrine of Equivalents in India, it did not provide a clear framework for its interpretation. The Court’s emphasis on the “substance” of the invention, rather than the literal language of the claims, laid the groundwork for future developments.

In the case of Sotefin SA v. Indraprastha Cancer Society & Research Center & Ors.,[7] the court, held even if each and every component of the patent specification is not found in the infringing products, it does not conclude that there is no infringement. The pith and marrow of the invention need to be looked into instead of meticulously focusing on the analysis of the patent claims verbatim. The court held the view that for determining the infringement, the court shall also apply the doctrine of equivalence to examine if the substituted element in the infringing product does the same work, in substantially the same way, to accomplish substantially the same result.

In the case of FMC Corporation &Ors. V. Natco Pharma Ltd.[8], the court held that “the doctrine of equivalents is applicable where a product or process is not identical to the claim granted in a patent, but its essential elements are sufficiently similar to the patented claim so as to construe the product or process as infringing the patent”. The factors that are to be taken for consideration in determining the patent infringement include the context of the patent, the prior art, the particular circumstances of the case and the purpose for which an ingredient is used in a patent, the qualities it has when combined with the other ingredients, and the function which it is intended to perform. When a patented invention is infringed by a product or process, then the minor differences in the non-essential features of the product or process would become irrelevant.

In Rxprism Health Systems Private Limited and another v Canva Pty Limited and others[9], the Court held that “If the infringing goods are made with the same object in view which is attained by the patented article, then a minor variation does not mean that there is no piracy. A person is guilty of infringement if he makes what is in substance the equivalent of the patented article. Some trifling or unessential variation has to be ignored.”

Recently, in the case of SNPC Machines Private Limited & Ors. v. Mr. Vishal Choudhary, the Court reinforced the framework for applying the Doctrine of Equivalents. The Court firmly rejected the notion that minor product variations preclude infringement. It was emphasized that attempting to deceive the patent system is unacceptable, and infringers cannot escape liability by simply noting minor differences between their products and the patented invention.

In order to establish a possible infringement, the pith and marrow test is to be used alongside the triple identity test. Further, based on the analysis of various precedents cited by the plaintiffs and defendant the Court laid down the key aspects that are to be considered when evaluating potentially infringing patent claims:

  • Claim Construction- Construction of the claims must be in a specific manner instead of mere literal construction,
  • Trifling Variations- Minor, unessential/ insignificant variations should be ignored
  • Equivalent effect- It must be determined whether the allegedly infringing product delivers the same effect as the patented invention
  • Claim- Product comparison- A comparison between products alone cannot conclusively determine infringement; instead, it is the comparison between the claims and the product that holds significance
  • Substance over Form- The pith and marrow of the invention should be the focus of the analysis, a meticulous analysis of the detailed specification, may not always be required
  • Function and Result- It is essential to determine if the infringing product performs the same function, in a similar manner, to achieve a comparable result.

Applying the triple identity test of ‘Function-Way-Result’, the Court observed that the substituted element in brick making machine of the defendant performed substantially the same function in substantially the same way to achieve substantially the same result[10]. The Court, while determining whether there was infringement, focused on the fundamentality functionality of the patented invention even though the infringing product employed slightly different mechanisms.

Way Forward

In the context of the evolving landscape of India’s patent jurisprudence, judicial consistency in applying the Doctrine of Equivalents is of paramount importance. This doctrine serves as a means of redressal for patentees, even in the absence of explicit infringement. Given the settled jurisprudence, the courts must now balance the scales between the protection of rights accorded to patentees and fostering a fair, competitive, and innovative marketplace. Such a predictable and transparent framework for the application of this doctrine will enhance legal certainty for patent owners and ensure that the patent system continues to stimulate innovation and ensure fair competition.

By Adv. Nishmma James

[1] MANU/DE/1825/2024

[2] Tarun Mathur (2007), Application of Doctrine of Equivalents in Patent Infringement Disputes Journal of Intellectual Property Rights Vol 12, pp 410-421 1

[3] ILR (1977) 2 Del 412

[4] (1967) 16 RPC 406

[5] (1979) 2 SCC 511

[6] (2008) 6 AIR Bom R(NOC 1103) 360

[7] 2022 SCC OnLine Del 516

[8] 2022 SCC OnLine Del 4249

[9] 2023 SCC OnLine Del 4186

[10] Pribish, R. (2006). Freedman Seating Co. And the Claim Vitiation Doctrine. https://core.ac.uk/download/225567330.pdf

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