Photon Wave v Seoul Viosys (CFI, 24 January 2025)

Dhenne Avocats · 10 October 2026

Our analysis

Summary

By an order of 24 January 2025 (UPC_CFI_238/2024), the full panel of the Paris Local Division, presided over by Judge Lignières, held inadmissible the standalone revocation action brought by Photon Wave against Seoul Viosys’s patent EP 3 404 726. Photon Wave had intervened in support of Laser Components, the defendant in infringement proceedings pending before the same division, without lodging a counterclaim for revocation in time. The order closes to the intervener the route of a separate revocation action before the division hearing the infringement case, while preserving its ability to attack the patent outside those proceedings.

Facts and procedure

Seoul Viosys sued Laser Components for infringement before the Paris Local Division on 5 December 2023 (UPC_CFI_440/2023). Photon Wave’s intervention was declared admissible on 12 February 2024. On 18 March 2024, the last day for the defence, Laser Components filed its defence without a counterclaim, while Photon Wave sought a right to counterclaim and an extension. By an order of 6 May 2024 the division held that the intervener was bound by the time limit applying to the defendant. Photon Wave then brought a revocation action before the Paris Central Division on 17 May 2024. On Seoul Viosys’s preliminary objection, that division transferred the case to the Local Division by an order of 5 January 2025. The Local Division had refused a stay on 24 July 2024 and fixed the infringement hearing for 13 March 2025.

The applicable law

Art. 33(4) UPCA assigns revocation actions to the central division, unless an infringement action between the same parties on the same patent is pending before a local division, in which case the action must be brought there. Art. 33(3) allows the infringement defendant to counterclaim for revocation, within the time limits of the written procedure (Rule 25.1). Rule 313.2 confines an intervener to supporting the procedural strategy of the party it supports, and Rule 361 allows a manifestly inadmissible action to be dismissed.

Question

May an intervener in an infringement action, which did not counterclaim for revocation in time, challenge the patent’s validity through a standalone revocation action before the local division hearing the infringement case?

Decision

The division first upheld its competence: the second sentence of Art. 33(4) UPCA requires the revocation action to be brought before the local division seised of parallel infringement proceedings, so lack of competence was not a ground for dismissal. It then set Rule 361 aside: the combined application of Arts. 32 and 33 and whether an intervener is a « party » remain debated, so the action was not manifestly inadmissible (paragraph 1).

On admissibility proper, the word « may » in Art. 33(3) gives the defendant a choice. Laser Components did not counterclaim, which it would have had to do before the local division within the written procedure, and these provisions do not conflict with the Rules of Procedure (paragraph 2). The Munich Central Division order relied on by Photon Wave, which concerned Art. 33(5), was irrelevant (paragraph 3). Fairness yields to efficiency: Photon Wave had access to the file from 20 February 2024 and sought more time only on the last day, without justification, it remains free to attack the patent outside the pending infringement proceedings (paragraph 4). The action was therefore inadmissible (paragraph 5). Photon Wave bears the costs, and Seoul Viosys’s request to raise the ceiling on recoverable costs by 50% was rejected (paragraph 6).

Key points for practice

• An intervener, confined to supporting the defendant’s strategy (Rule 313.2), cannot make up for the absence of a counterclaim by a standalone revocation action before the local division hearing the infringement case.
• The local division’s competence over the revocation action under Art. 33(4) does not in itself make the action admissible.
• The written-procedure time limit applying to the defendant binds the intervener, which rules out dilatory strategies.
• Practical point: an intervener wishing to contest validity must act within the defence deadline or have the defendant lodge the counterclaim.

Provisions applied

Agreement on a Unified Patent Court

Art. 32(1), Art. 33(3), (4) and (5), Art. 69 and Art. 73(1)

Rules of Procedure

Rules 25.1, 42, 152, 220.1(a), 224.1(a), 313.2 and 361

Case law cited

Paris Local Division, 13 March 2024 (UPC_CFI_440/2023), Seoul Viosys v Photon Wave, Paris Local Division, 6 May 2024, Munich Central Division (UPC_CFI_1/2023), Paris Central Division, 5 January 2025

Related decisions

• Seoul Viosys v Photon Wave, 6 May 2024, earlier order on the intervener’s time limit for a counterclaim.

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.