Seoul Viosys v Photon Wave (CFI, 6 May 2024)

Dhenne Avocats · 10 October 2026

Our analysis

Summary

By an order of 6 May 2024 (UPC_CFI_440/2023, ACT_588685/2023, ORD_18404/2024), the judge-rapporteur of the Paris Local Division (C. Lignières), in the infringement action on EP 3 404 726 brought by Seoul Viosys Co., Ltd against Laser Components SAS, held that the intervener Photon Wave Co., Ltd., the defendant’s supplier, had not lodged a counterclaim for revocation in time and refused both an extension of time and a change of language. The order defines the intervener’s place: it supports a party and does not run a defence of its own.

Question

May an intervener supporting the defendant lodge on its own a counterclaim for revocation which the defendant did not bring, or obtain time to do so, and may it obtain a switch of the proceedings to English?

Decision

An intervener may not take a procedural position different from that of the party it supports. The defendant had three months to lodge its Statement of defence and any counterclaim for revocation (Rules 23 and 25.1 RoP), it filed in time without a counterclaim, and Photon Wave lodged none within the same period. No serious reason justified an extension (Rules 9.2 and 9.3(a) RoP). The request to change the language, examined under Art. 49(4) UPCA and Rule 322 RoP, was rejected: the parties did not agree, the choice of French respected the rights of the French defendant, and the nationality of the intervener or its representative was not a sufficient reason. The value of the action and the explanations on the TESCAN report were left to the interim procedure (Rule 104 RoP), Seoul Viosys’s request to postpone its time limit for the Reply was rejected.

Key points for practice

• Practical point: the counterclaim for revocation belongs to the defendant and must be lodged within the time for the Statement of defence, a supplier intervening on its side cannot make up for its silence.

Provisions applied

Agreement on a Unified Patent Court

Art. 33(4), Art. 49(4) and Art. 69

Rules of Procedure

Rules 9.2, 9.3(a), 13.2, 23, 24, 25.1, 104, 220.2, 313, 315.4 and 322

Case law cited

Sanofi-Aventis Deutschland v Amgen, Court of Appeal, 13 October 2023 (UPC_CoA_320/2023)

Prepared by Dhenne Avocats from the official decision, consulted on 10 October 2026. The database is updated every week, on Friday. Only the official text is authoritative.