Court overturns interim injunction in telecom patent prior art dispute

In its recent decision on Sterlite Technologies Limited v HFCL Limited (CS (COMM) 19/2022), the Delhi High Court has vacated the ex parte interim injunction previously awarded to Sterlite, which had restrained HFCL from selling products that allegedly infringed on Sterlite’s patent (IN335369) relating to optical fibre cables (OFCs).

The injunction had been operative since 12 January 2022. HFCL filed an interim application to vacate the order assailing the interim injunction on the grounds of invalidity of the patent in suit and non-infringement. With respect to the former, HFCL submitted two prior art product brochures on novelty and inventive step: a “multi-loose tube, single sheath, micro-cable” by Reliance Jio Infocomm Limited (RJIL) and a “Gigacom air blown micro-cable” by Gigacom. The court conducted a comparative analysis of certain features and summarised the result.

Sterlite argued that novelty and inventive step lay primarily in the strengthening layer, and that the patent covering the use of aramid yarn for this was an innovative feature. While analysing the prior art documents, the court held that the use of the same language is unnecessary in order for it to defeat novelty or to show a lack of inventive step. It is possible that different terminologies or similar material is used in the prior art. With this principle in mind, the court noted that the water swellable yarn feature in the suit patent was disclosed as a water blocking yarn in the Gigacom optical fibre cable prior art. Further, the court noted that the feature, claimed by Sterlite to be novel and inventive (ie, the cross-binding yarn), was a common feature in all the documents and thus not a distinguishing one. Even the fibre count (the ‘369 patent has 16 fibres while RJIL optical fibre cable has multiples of six and Gigacom optical fibre cable has multiples of 12) could not sufficiently distinguish the patent in suit from the prior art. Therefore, the court’s opinion was that the differences highlighted by Sterlite were not sufficient to find the ‘369 patent presumptively valid.

The non-infringement ground that HFCL adopted hinged on the assertion that the number of optical fibres used in their product was 12 and not 16 (as required by the ‘369 patent). Sterlite’s position was that the number of optical fibres in claim one , which was 16, was merely illustrative and that the use of 12 fibres would infringe on the ‘369 patent. HFCL relied on two patent applications filed by Sterlite (Applications 201621010853 and 2209/MUM/2015) to support its assertion that differences in the number of optical fibres was a non-infringing alternative. In the first application, Sterlite specifically claimed that there were 24 optical fibres, whereas the second application merely recited a “plurality” of them. Therefore, HFCL’s subsequent contention was that Sterlite was conscious of the difference in the number of optical fibres. Thus, the number 16 may not merely be illustrative, as Sterlite had suggested.  The court agreed.

As a result, the court – mentioning that the observations were merely prima facie in nature and will not bind the trial of the suit – held that Sterlite had not made a successful case of being entitled to the interim injunction. The ex parte interim injunction was therefore vacated.