A recent decision1 by the Delhi High Court has provided clarity on various issues of patent law that had not been examined by Indian courts so far. These include parallel imports' exemption under the Patents Act, 1970, the doctrine of equivalence and enforceability of a patent towards its expiry.

In the present matter, Sotefin SA filed a suit for infringement of its registered patent for "carriage for the horizontal transfer of motor vehicles in automatic mechanical car parks" against multiple defendants. The suit patent for the plaintiff's product, commonly known as a dolly or a silomat dolly, was registered in March 2002 and was valid until March 2022.

During the validity of the patent, the plaintiff came across pictures of the defendants' smart dollies, which resembled the plaintiff's silomat dollies and asserted its rights against the defendants. The court then appointed a team of scientific experts to compare elements of the parties' respective dollies with a view to ascertaining whether the plaintiff's patent was infringed.

Based on the report submitted by the scientific advisors, the plaintiff argued that this was a case of infringement since seventeen (17) of the nineteen (19) sub-elements between the respective dollies were common. The plaintiff argued that the claims in the suit patent had identical input-output functions to the smart dollies since both had the same end result of acting as dollies for cars. The defendants, however, disputed these claims. They argued that two (2) essential elements were absent in their smart dollies. Further, the plaintiff had adopted an incorrect test of comparing the rival products, as opposed to comparing the smart dollies to each of the claims of the suit patent. The defendants further argued that they imported the dollies into India and were, thus, exempted from liability due to the "Bolar Exemption".

The crucial question before the court was to determine whether the two (2) dissimilar elements between the dollies were "essential" in determining infringement of the patent. The court, based on arguments by both parties, held that the absence of the two (2) elements could not be construed to be so essential that it would render the dollies to be substantially different. It noted that there could be cases of non-literal infringement, where each and every component of the patent specification is not found in the infringing products. However, this does not rule out infringement altogether. Pertinently, the court noted that it is the pith and marrow of the invention which is to be looked into while comparing the specifications. It also emphasized that patent protection is territorial in nature and that importing a product that infringes an existing patent is against the Indian patent regime.

On the issue of granting an injunction in the plaintiff's favour based on its rights in a patent that is close to expiry, the court observed that the monopoly granted to exploit the invention, without competition, during the term of the patent was available even when the patent was on its last legs. It stated that Indian patent law does not make any distinction between a new or a concluding term. Rather, the benefit of registration is applicable to the entire term of the patent. Thus, the court stated that it is duty bound to enforce rights of a patent holder during the term of the patent, irrespective of the balance period of the term of the patent.

Ultimately, the court granted an interim injunction in favour of the plaintiff, restraining the defendant from making, selling, exporting, importing, or offering for sale, smart dollies, which were found to be infringing on the plaintiff's silomat dollies.

Footnote

1. CS(COMM) 327/2021

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